Version 0.178. Last updated 11 th September 7 March 2010.
The following document defines the language which will be used for communications between a client and server, and for negotiation between two clients, in the Diplomacy AI Development Environment project. Statements which use “will”, “shall” or “must” are mandatory, and must be observed. Statements which use “may” or “can be” are recommended, but cannot or will not be enforced.
The syntax is split into a number of levels. Each level completely includes all previous levels. The levels are:
Level 0: No Press
Level 10: Peace and Alliances
Level 20: Order proposals
Level 30: Multipart Arrangements
Level 40: Sharing out the Supply Centres
Level 50: Nested Multipart Arrangements
Level 60: Queries and Insistencies
Level 70: Requests for Suggestions
Level 80: Accusations
Level 90: Future Discussions
Level 100: Conditionals
Level 110: Puppets and Favours
Level 120: Forwarding Press
Level 130: Explanations
Level 140: Sending Emotional State
Level 150: Requesting and Demanding Offer
Level 160: Utility Bounds
All Bots must implement the commands in all levels – they should not assume that they will never be playing in a game that is above the level they are designed for. Where a Bot receives a message that is above its intended level, there is a response it can use to indicate this.
The Diplomacy AI Development Environment Message Syntax is based on the structure and syntax of the DPP Language written by Danny Loeb. However, a significant number of changes have been made from the DPP Language in order to make it more powerful and more consistent.
There are a number of terms which are used by a lot of commands. They are:
Power – can be one of AUS, ENG, FRA, GER, ITA, RUS, TUR. These may be changed for variants other than Standard - see the MAP token.
Province – can be one of ADR, AEG, ALB, ANK, APU, ARM, BAL, BAR, BEL, BER, BLA, BOH, BRE, BUD, BUL, BUR, CLY, CON, DEN, EAS, ECH, EDI, FIN, GAL, GAS, GOB, GOL, GRE, HEL, HOL, ION, IRI, KIE, LON, LVN, LVP, MAO, MAR, MOS, MUN, NAF, NAO, NAP, NTH, NWG, NWY, PAR, PIC, PIE, POR, PRU, ROM, RUH, RUM, SER, SEV, SIL, SKA, SMY, SPA, STP, SWE, SYR, TRI, TUN, TUS, TYR, TYS, UKR, VEN, VIE, WAL, WAR, WES, YOR. Alternative abbreviations must not be used. These may be changed for variants other than Standard - see the MAP token.
Coast – can be one of NCS, ECS, SCS, WCS.
Season and Phase – can be one of SPR (Spring Moves), SUM (Spring retreats), FAL (Fall Moves), AUT (Fall retreats), WIN (Adjustments).
Unit type – can be one of AMY, FLT.
In the text, anything in [square brackets] may be omitted. Anything which is specified twice followed by a line of dots ... may be repeated any number of times (including once), but not including not at all unless it is also in [square brackets].
Any (round brackets) are part of the syntax of the language.
Internally, all tokens are represented as a 16-bit value. Details of the value for each token are provided in the Client-Server Protocol Document. Conversion between 16-bit values and text can be done. All text versions of the tokens are 3 characters long, alphabetic only, and not case-sensitive.
In this section, we just have the syntax required for getting a game up and running, ordering, retrieving results, and general game management.
NME ('name') ('version')
This should be sent by the client to the server as soon as it has connected. It contains the name and version of the client. Both name and version are text fields. They may any printable character. The Server will respond with YES(NME('name') ('version')), or REJ (NME ('name') ('version')) if the game has already started.
The name and version are stored by the Server, for storing game records when the game ends. It is not possible for a client to request information about which client is playing each power.
OBS
This is sent by the client to the server in place of NME, to indicate that the connected client is actually just an observer, and doesn’t wish to take part in the game. Observers are informed of the game progress as turns process, but do not take any part in the game. The server will respond with YES (OBS).
IAM (power) (passcode)
This is sent by the client to the server in place of NME, to indicate that the client is rejoining the game following a loss of connection. Passcode is the passcode which was sent to the client by the server in the original HLO message at the start of the game. The server will reply with YES (IAM (power) (passcode)) if the takeover is allowed, or REJ (IAM (power) (passcode)) if the passcode is wrong, the game is not waiting for a replacement of the specified power, or the game has not started. Following a successful IAM message, a MAP and HLO message are NOT sent. The client is straight into the game where it left off. Note that there may have been messages which were lost as the connection broke. These messages will not be resent on reconnection. Until a successful NME, OBS or IAM message has been received, the client will be treated the same as an observer, except that messages will not be sent to the client except in response to messages from the client (e.g. ORD, NOW, SCO, etc will not be sent). The one exception to this is OFF, which may be sent to a client before a successful NME, OBS or IAM message has been received.
MAP ('name')
Once the client has joined the game, the MAP token is sent to specify the map which is to be used, as soon as the HLO or OBS has been received and acknowledged. The name is unique to the map - so if the client has played a game on a map with this name before, then this will be the same map again. The Standard map is called 'standard'. name can include only letters, numbers and underscore. Map names are not case-sensitive.
The client may request another copy of the MAP message at any time, by sending MAP with no parameters.
The client should respond with YES(MAP ('name')) if it is to play on the map, or REJ (MAP ('name')) if the client can not cope with the requested map.
If the client does not know the map, then instead of replying with YES (MAP ('name')) or REJ (MAP ('name')), it can request the map definition with :
MDF
The server will reply with the map definition of the form: MDF (powers) (provinces) (adjacencies)
(powers) is the list of powers. e.g. (AUS ENG FRA GER ITA RUS TUR).
(provinces) is the list of provinces. This is broken further into two sections - ((supply centres) (non supply centres)). (supply centres) is of the form ( (power centre centre ...) (power centre centre ...) ...) where centre is a supply centre province, and power is the power which the centre is a home centre for. power is UNO for neutral supply centres. Also, in the unusual case of a variant where a supply centre is a home centre for two or more powers, power may be of the form (power power ...). Note that the home centres are the locations where a power may build new units, but are not necessarily the location where the units start the game. (non supply centres) is the list of all non-supply-centre provinces.
(adjacencies) is the list of what is next to what. It is of the form ((prov_adj) (prov_adj) ...).
(prov_adj) is of the form (province (unit_type adj_prov adj_prov ...) (unit_type adj_prov adj_prov ...) ...).
unit_type is one of:
AMY - list of provinces an army can move to
FLT - list of provinces a fleet can move to
(FLT coast) - list of provinces a fleet can move to from the given coast.
adj_prov is one of:
province - a province which can be moved to
(province coast) - a coast of a province that can be moved to.
The type of a province can be determined from its adjacencies. An inland province only has army adjacencies. A sea province only has fleet adjacencies. A coastal province has both. A multi-coastal province has entries for each coast.
Note that for a land province surrounded by sea, there will be an AMY entrance with no provinces listed.
So, the map for Standard would (with some provinces skipped, and carriage returns added for clarity):
MDF (AUS ENG FRA GER ITA RUS TUR) (((AUS TRI BUD VIE) (ENG LON LVP EDI) ... (UNO POR SPA TUN BEL HOL ...)) (ADR AEG ALB APU ...))((ANK (FLT ARM BLA CON) (AMY CON SMY ARM)) (ADR (FLT ION ALB TRI VEN APU)) (CON (AMY BUL SMY ANK) (FLT BLA (BUL ECS) (BUL SCS) AEG SMY ANK)) (BUL (AMY GRE SER RUM CON) ((FLT ECS) RUM BLA CON) ((FLT SCS) CON AEG GRE)) (BOH (AMY TYR MUN SIL GAL VIE)) ...)
No map will ever contain a province abbreviation which is also has a defined meaning in the Diplomacy AI Development Environment syntax, except that the tokens for provinces and powers on the Standard map may be reused on variant maps.
No map will ever contain more than 256 provinces.
Once the client has received the Map Definition, it should then reply with YES (MAP ('name')) if it is able to use the map, or REJ (MAP ('name')) if it is not. If the client wishes to do some processing on the map before the game starts, then it should do this before sending YES (MAP ('name')).
The client can send the NOW and SCO commands to the Server to determine the supply centre ownership and starting positions for the variant. See below for details.
Note that for some variants, the map name may be different, but the actual map is the same as another variant (for example, for Fleet Rome). When this occurs, it can not be assumed that the supply centre ownership and starting positions will be the same as for the other variants which use the same (but differently named) map.
On all maps, the condition for a solo is having more than half the supply centres in the game. So for a map which has 34 or 35 centres, the victory condition is 18 centres.
HLO (power) (passcode) (variant)
The Server sends this to each client when the game starts. power is the power to be played by this client, or UNO for an observer. passcode is an integer value which is required to rejoin the game. variant is of the form (variant option) (variant option)..., and contains the details of any options for the game.
e.g. HLO (ENG) (1234) ((LVL 20) (MTL 1200))
This client is England. Its passcode is 1234. This is a level 20 game, with 20 minutes (1200 seconds) per movement turn. variant option can be any of the following:
LVL n – game is of syntax level n. This variant option will always be specified.
MTL seconds – maximum number of seconds available for movement turns. If not specified, there is no time limit.
RTL seconds – maximum number of seconds available for retreat turns. If not specified, there is no time limit.
BTL seconds – maximum number of seconds available for build turns. If not specified, there is no time limit.
DSD - deadline stops on disconnection. If a client disconnects when it has orders due, the deadline timer stops.
AOA – Any orders accepted. Any orders which match the syntax for an order, and are for a unit owned by the client sending the order, will be accepted, whether they are legal or not. If not specified, then only orders which could be valid will be accepted. In an AOA game, any token which would normally be given as a THX note can instead be used as an ORD result.
Further variant options are added in Level 10.
The variant options will always be specified in the order they appear in this document.
The client can send the command HLO to the server with no arguments at any time. The server will reply by sending another copy of the HLO message, or REJ (HLO) if the game hasn’t started.
SCO (power centre centre...) (power centre centre...) ...
This is sent from the Server to each client at the start of the game, and after each Fall Retreat turn (or Fall Movement turn if there are no retreats). It indicates the current supply centre ownership. Unowned centres are listed against the power name UNO. E.g. at the start of the game:
SCO (AUS BUD TRI VIE) (ENG LPL EDI LON) (FRA BRE MAR PAR) (GER KIE BER MUN) (ITA ROM NAP VEN) (RUS STP MOS WAR SEV) (TUR ANK CON SMY) (UNO NWY SWE DEN HOL BEL SPA POR TUN GRE SER RUM BUL)
The client can send the command SCO to the server with no arguments at any time. The server will reply by sending another copy of the latest SCO message, or the starting supply centre ownership if the game hasn’t started.
NOW (turn) (unit) (unit) ...
This is sent from the server to the client at the start of the game, and after every turn. It indicates the current turn, and the current unit positions. E.g. at the start of the game :
NOW (SPR 1901) (AUS FLT TRI) (AUS AMY BUD) (AUS AMY VIE) (ENG FLT LON) ...
Units in bicoastal provinces have a province and coast bracketed together. E.g.:
(RUS FLT (STP SCS))
Before a retreat turn, units may have a list of retreat options, prefixed by MRT (Must retreat to). E.g. (ENG FLT NTH MRT (LON YOR EDI NWG))
If the unit has no possible retreats, then the unit will still be listed, and the client still must order the disband. E.g.
(ENG FLT NTH MRT ())
Retreat options will include a coast if a fleet can retreat to a multi-coastal province. e.g.
(TUR FLT CON MRT (BLA SMY (BUL ECS) (BUL SCS)))
The client can send the command NOW to the server with no arguments at any time. The server will reply by sending another copy of the latest NOW message, or the starting position if the game hasn’t started. HST (turn) Any previous turn’s results may be requested by sending an HST command to the server with the turn as a parameter (e.g. HST(SPR 1901) ). The server will reply by sending the ORD messages for that phase, followed by SCO and NOW messages to give the position after the turn requested. SCO will be sent after every HST command, not just those where supply centre ownership changes. REJ (HST (turn))** is sent if the requested turn doesn’t exist.
SUB (order) (order) ...
SUB (turn) (order) (order) ...
This is sent from the client to the server, to submit orders for the next turn. The second form will check that the turn stated is the current turn (i.e. the turn sent in the most recent NOW message), and will reply with REJ (SUB (turn) (order) (order) ...) if this is not the case
order can take the following form:
Movement phase orders.
| Format | Order |
|---|---|
| (unit) HLD | Hold |
| (unit) MTO province | Move |
| (unit) SUP (unit) | Support to hold |
| (unit) SUP (unit) MTO prov_no_coast | Support to move |
| (unit) CVY (unit) CTO province | Convoy |
| (unit) CTO province VIA (sea_province sea_province ...) | Move by convoy |
Retreat phase orders
| Format | Order |
|---|---|
| (unit) RTO province | Retreat to |
| (unit) DSB | Retreat off the board |
Build phase orders
| Format | Order |
|---|---|
| (unit) BLD | Build unit |
| (unit) REM | Remove unit |
| power WVE | Waive build |
unit is a unit, and must be in the form as given by the NOW command – i.e. power type province – e.g. ENG FLT LON. Where a unit is a fleet in a multi-coasted province, the coast must be specified. province is any province. For a fleet moving to a province with multiple coasts (Spain, StP or Bul in Standard), it must be of the form (province coast).
prov_no_coast is a province with no coast specification.
sea_province is a province where a fleet may be to convoy. The provinces must be listed in the order that the army will pass through them.
Examples:
SUB ((ENG AMY LVP) HLD) ((ENG FLT LON) MTO NTH) ((ENG FLT EDI) SUP (ENG FLT LON) MTO NTH)
SUB ((ENG FLT BAR) MTO (STP NCS)) ((ENG FLT NWY) SUP (ENG FLT BAR) MTO STP)
SUB ((ITA AMY TUN) CTO SYR VIA (ION EAS)) ((ITA FLT ION) CVY (ITA AMY TUN) CTO SYR) ((ITA FLT EAS) CVY (ITA AMY TUN) CTO SYR)
SUB ((ENG AMY YOR) CTO NWY VIA (NTH)) ((ENG FLT NTH) CVY (ENG AMY YOR) CTO NWY) ((ENG FLT NWG) SUP (ENG AMY YOR) MTO NWY)
SUB ((ITA FLT NAP) BLD)
SUB ((RUS FLT GOB) REM)
All unused builds must be waived, even if they are unusable.
The Server will reply to each order (not each message), in left to right order through the orders, with a THX message. This is of the format:
THX (order) (note)
order is the order as submitted. note is one of the following:
| Order | Message |
|---|---|
| MBV | Order is OK. |
| FAR | Not adjacent. |
| NSP | No such province |
| NSU | No such unit |
| NAS | Not at sea (for a convoying fleet) |
| NSF | No such fleet (in VIA section of CTO or the unit performing a CVY) |
| NSA | No such army (for unit being ordered to CTO or for unit being CVYed) |
| NYU | Not your unit |
| NRN | No retreat needed for this unit NVR Not a valid retreat space |
| YSC | Not your supply centre |
| ESC | Not an empty supply centre HSC Not a home supply centre NSC Not a supply centre |
| CST | No coast specified for fleet build in StP, or an attempt to build a fleet inland, or an army at sea. |
| NMB | No more builds allowed |
| NMR | No more removals allowed |
| NRS | Not the right season |
Alternatively it will reply with REJ (SUB (order) (order) ... ) if the game has not started.
Any order which receives a note other than MBV has been rejected by the server, and a corrected order should be submitted in its place.
Movement and retreat orders can be changed by giving a new order for a unit. Builds and retreats can be cancelled by ordering NOT (SUB (order)). The Server will reply to this with YES (NOT (SUB (order))), or REJ (NOT (SUB (order))) if the order cannot be cancelled. Alternatively, an entire turns orders can be cleared with NOT (SUB), which the Server will reply to with YES (NOT (SUB)).
MIS (unit) (unit) ... MIS (unit MRT (province list)) (unit MRT (province list)) ... MIS (number)
This command can be sent by the Server immediately after the last THX message following a SUB command. If sent, it indicates that it does not have a full set of orders. The first form is used during a movement phase, and indicates the list of units which have not been ordered. The second form is used during a retreat phase, and indicates the list of dislodged units which have not been ordered. The third form is used during a build phase. If number is positive, it indicates that the client must order that many more disbands. If number is negative, it indicates that the client must order that many more builds. The first two forms of the MIS command use exactly the same parameter format as the NOW command. The client may request a copy of the current MIS command by sending MIS with no parameters. The server will respond with REJ (MIS) if the game has not started or has ended. If there are no outstanding orders, then the Server will reply with MIS with no parameters.
NOT(GOF)
This is sent by the client to the server. It means don’t process orders until the deadline. It is the equivalent of set wait on the judges. The server will reply with YES(NOT(GOF)), or REJ(NOT(GOF)) if the game has not started, the power has been eliminated, or the game has ended.
GOF
Go ahead and process orders when everybody is in. Server will reply with REJ(GOF) if the game has not started or has ended, or YES(GOF) if everything is OK. It will immediately follow this with MIS(...) (as when an incomplete set of orders is submitted – see SUB) if not all orders are in for this player.
If the client does not send GOF or NOT (GOF) during the turn, the server will assume the client is ready to process as soon as the client has submitted a complete set or orders (i.e. GOF is assumed each turn).
ORD (turn) (order) (result)
This is sent by the Server when the turn has processed. turn is the turn which has just processed. order is an order submitted by a player. One ORD message is sent per unit for a movement phase, one per retreat for a retreat phase, and one per build/disband/waive for a build phase . It has exactly the same format as in the SUB and THX commands.
result is the result of the order. It can be one of the following:
| Order | Meaning |
|---|---|
| SUC | Order succeeded (can apply to any order). |
| BNC | Move bounced (only for MTO, CTO or RTO orders). |
| CUT | Support cut (only for SUP orders). |
| DSR | Move via convoy failed due to dislodged convoying fleet (only for CTO orders). |
| NSO | No such order (only for SUP, CVY or CTO orders). |
In addition, a second token may be included :
RET Unit was dislodged and must retreat.
In the case of a unit which was convoying or holding, RET may be the only token.
Retreat orders will always have a result of SUC or BNC. BNC indicates the unit was destroyed by a bounced retreat.
Build orders will always have a result of SUC.
Waived builds are reported as (power WVE) for the order. E.g.:
ORD (WIN 1901) (RUS WVE) (SUC)
If a power waives multiple builds, then multiple waive ORD messages are sent.
When the turn processes, the series of ORD messages will be immediately followed by a SCO (if the centre ownership has just been updated) and a NOW message. The NOW message will always be the last message in this sequence.
Turns may be skipped (e.g. a retreat turn where nobody has any retreats). The NOW message indicates which is the next turn.
The previous turn’s results may be requested by sending an ORD command to the server with no parameters. The server will reply by resending the last movement turn’s ORD message, and any subsequent Retreat or Build ORD messages, or REJ (ORD) if the game has not started or the first turn has not yet processed.
SVE ('gamename')
The Server can send this at any point. It is a request for the client to save the current game with the name given. gamename will never be more than 8 characters, and can include only letters, numbers and underscore. Game names are not case-sensitive. The client should save everything it will need in order to be able to resume the game at a later date. Once the game is saved, the client should respond with YES (SVE ('gamename')). If there is an error saving the game, then it should respond with REJ (SVE ('gamename')). Once the game has been saved, the client should continue playing.
LOD ('gamename')
The server can send this to the client instead of sending a HLO message. It indicates that the game specified is to be loaded and restarted, rather than a new game started. See SVE for details of gamename. The client should load the game and then respond with an IAM command (as detailed above), and then start playing from the loaded position. If the game can not be reloaded (e.g. because a game with that name has never been saved), then it should respond with REJ (LOD ('gamename')).
If a client fails to reload the game, then the game will be started and the client in question will immediately be placed in CD.
Note that the client does not need to store the current game position, as it can immediately send the commands HLO, NOW, SCO, and ORD to find out the state of the game. All that needs to be stored, is the power being played, the passcode as provided by the HLO command, and details of past press and alliances that the client wishes to store.
OFF
This command is sent by the Server, and indicates that the client should exit. The client should exit without replying.
TME (seconds)
This message is sent by the server, in games where there is a time limit for the turn. It indicates the number of seconds until the next deadline. It is sent immediately after each turn has processed (i.e. after the ORD, SCO (where appropriate), and NOW messages).
In addition, the client can request TME to be sent at other times. To do this, the client sends TME (seconds) to the server. The server responds with YES (TME (seconds)) to confirm this, or REJ (TME (seconds)) if seconds is negative, or is longer than the length of the longest deadline, or if there are no deadlines. The server will then send TME (seconds) to the client, seconds seconds before the deadline, every turn.
Having requested a TME message, the client can cancel it with the message NOT (TME(seconds)). The server will respond with YES (NOT(TME(seconds))) to confirm it has been cancelled, or REJ(NOT(TME(seconds))) if there was no such time request. Alternatively the client can send NOT(TME) to request that all TME requests are cancelled. This will always be responded to with YES(NOT(TME)).
Also, the client can send the message TME with no parameters. The Server will respond with TME (seconds) where seconds is the time to the next deadline, or REJ (TME) if there are no deadlines.
The client should not acknowledge the TME message from the server.
PRN (message)
This message is sent from the server to the client, and indicates that message was received from the client by the server, but does not have a correct set of parentheses. The PRN message will also not have matching parentheses. The client should cope with this. No reply should be sent to the server.
HUH (message)
This message is sent from the server to the client, and means that the server determined that message had a syntax error in it. The token ERR is inserted into the message immediately before the first offending token.
This error can also be caused by trying to use a form of the Diplomacy AI Development Environment syntax which is not available at the syntax level for the current game.
The PRN and HUH messages may also be sent from the client to the server, if the AI believes that a message from the server is incorrectly bracketed, or contains illegal syntax. However, the server and the client must not send HUH or PRN in response to a HUH or PRN message.
CCD (power)
This message is sent from the server to the client, and indicates that the specified power has been declared to be in Civil Disorder. This will normally happen because either the power failed to get its orders in by the deadline, or because the TCP/IP connection to the client has been broken. If the power returns, the server will send the command NOT(CCD(power))
If the game is of the DSD variant, then when a power disconnects which has not yet submitted orders, then server sends NOT (TME( seconds )) immediately after the CCD message to indicate that the deadline timer has stopped, and sends TME( seconds ) following the NOT(CCD( power )) message when the timer restarts.
ADM ('name') ('message')
This message is sent from the Client to the Server, and contains an admin message - i.e. a message to do with the running of the game (e.g. I'm having connection problems, or Server going down, or I have to leave shortly). It can be sent by any client - player or observer, and can be sent before, during or after the game. It should not be used for negotiation. The Server will forward the message to every client. The Server may be configured to refuse Admin messages, in which case it will reply to the Client with REJ (ADM ('name') ('message')).
SLO (power)
This command is sent from the server to the client, and indicates that the game has ended due to a solo by the specified power. It is sent after the SCO message and before the NOW message.
DRW
This command is sent by the client to the server, to indicate that the client would accept a DIAS draw at this point. The server responds with YES (DRW) , or REJ(DRW) if the game has not started or has ended, or the message is received from an eliminated power or an observer.
DRW can also be sent from the server to the client, to indicate that a draw has been declared. This will happen as soon as all non-eliminated clients have simultaneously indicated that they will accept a draw at that point.
If a turn processes after DRW is sent from the client to the server, then the command is ignored. The client must resend the command each turn it continues to want a draw.
The DRW command is extended in level 10.
NOT (DRW)
This command cancels any DRW message which has been sent previously by this client. The server will respond with YES (NOT(DRW)), except if the game has not started, has finished, the power is eliminated, or is an observer in the game, when it will respond with REJ(NOT(DRW)).
SMR (turn) (power (‘name’) (‘version’) centres [year_of_elimination] ) (power (‘name’) (‘version’) centres [year_of_elimination] ) ...
The message is sent from the server to the client immediately after the SLO or DRW message, and informs the client as to who was playing each power. centres is the number of centres held by the power at the end of the game. If this is 0 then year_of_elimination is included, and is the year that the power dropped to 0 centres.
In this level, we add some very basic press between powers.
In addition to the previous variant options, the following may also be given at the start of the game:
PDA – Partial draws are allowed (i.e. No DIAS).
NPR – No press during retreat phases
NPB – No press during build phases
PTL seconds – number of seconds before a movement deadline that all press between powers must stop. If not specified, then 0.
In a PDA variant game, the client can send the DRW command with a parameter – the list of powers in the draw:
DRW (power power power ...)
If all surviving powers submit a DRW command with the same list of powers on the same turn, then a draw is immediately declared including those powers.
Multiple DRW commands may be submitted, each one does not supersede previous DRW messages. Instead it adds an additional draw combination which the power will accept.
The Server will respond to each DRW message with YES(DRW(power power power ...)), or REJ(DRW(power power power ...)) if the game has not started, or if the list of powers includes an eliminated power.
When a draw is declared in a PDA variant game, the draw message includes a parameter – the list of powers in the agreed draw. The client may still send a DRW command without a parameter in a PDA game – it is the same as sending a DRW command listing all surviving powers.
The client can cancel a partial draw request with NOT (DRW (power power power...)). Sending NOT( DRW ) cancels a DRW sent with no parameters, but does not cancel a DRW sent with a list of powers.
SND (power power ...) (press_message)
SND (power power ...) (reply)
SND (turn) (power power ...) (press_message)
SND (turn) (power power ...) (reply)
These are sent by the client to the server, to send press_message to the list of countries given. The recipient list must not include the sending power.
For the third and fourth forms, the server will check that turn is the current turn (i.e. the turn sent in the most recent NOW message), and will reply with REJ(SND (turn) (power power ...) (press_message) ) or REJ (SND (turn) (power power ...) (reply) ) if this is not the case.
The message sent applies to the current turn, unless indicated otherwise by the contents of the message. The server will reply with one of the following:
CCD (power)
power is in CD, and so can not receive press. If multiple powers are listed in the SND command, and the client receives a CCD reply, then the message has not been sent to anybody (including the ones that are not in civil disorder).
OUT (power)
power has been eliminated from the game. If multiple powers are listed in the SND command, and the client receives an OUT reply, then the message has not been sent to anybody (including the ones that have not been eliminated).
HUH (SND (power power ...) (press_message))
HUH (SND (turn) (power power ...) (press_message))
Syntax of the SND message is illegal. This may be a genuine syntax error, or it may be because press_message contains a token which is not allowed at the language level of the game. ERR is inserted immediately before the first token to cause an error. See HUH in Level 0 for details.
REJ (SND (power power ...) (press_message))
REJ (SND (turn) (power power ...) (press_message))
Either the game has not started, or it is a retreat phase in a NPR variant game, or a build phase in a NPB variant game, is past the press deadline in a PTL variant game, or the sending power has been eliminated or is in the recipients list.
YES (SND (power power ...) (press_message))
YES (SND (turn) (power power ...) (press_message))
The message was sent successfully.
When the message is sent successfully, the target powers will receive the message in one of the following forms:
FRM (power) (power power ...) (press_message)
FRM (power) (power power ...) (reply)
The first power is the power which sent the message. The power list and the press_message are as in the SND command. Note that if the SND message contained a turn parameter, this isn't included in the FRM message. We have now covered every command in the Diplomacy AI Development Environment syntax. The remainder of this document covers the contents of press_message and reply.
Sequences of press messages can be split into two categories. They can be attempting to form an agreement between a number of powers, or they can be providing or requesting information. Agreements are formed by one power proposing an arrangement to a number of other powers (either using the PRP (level 10) or the INS (level 60) tokens). For the arrangement to be agreed, each of the receiving powers must reply to the sending power plus all of the other receiving powers, accepting the proposal (using the YES (level 10) token).
Most arrangements apply to a single turn. Where this is not the case, it is indicated in the description of the arrangement. If a proposal is made in one turn, but accepted in a subsequent turn, then the turn or turns it applies to are calculated based on the time at which the original proposal was sent, not the time at which it was agreed. Powers should not attempt to form an agreement over a proposal which is wholly in the past, or which has already been breached.
In some cases, the order in which a number of press messages occurred is important. Where this is the case, each power should consider the order in which it received the confirmations of its own messages, and the messages from the other powers, from the server. It is guaranteed that this order will be the same for all powers.
Where a number of agreements are made which conflict with each other, the latter agreement takes precedence. This has a number of effects, including the ability to unmake an agreement by making a conflicting agreement.
press_message = PRP (arrangement)
This indicates that the sending power is proposing an arrangement. Some offers represent specific actions, while others (e.g. PCE) represent concepts, and as such, only have a vague definition. arrangement can be in one of the following forms:
arrangement = PCE (power power power ...)
Arrange Peace between the listed powers. Eliminated powers must not be included in the power list. The arrangement is continuous (i.e. it isn’t just for the current turn).
arrangement = ALY (power power ...) VSS (power power ...)
Arrange an Alliance between the powers in the first list. The second list is the powers to ally against. Eliminated powers must not be included in either power list. The arrangement is continuous (i.e. it isn’t just for the current turn).
arrangement = DRW
Arrange a Draw. In the case of a PDA game, this may also be DRW (power power power ...). The list of powers must include at least two powers. Eliminated powers must not be included in the power list.
arrangement = SLO (power)
Propose a Solo to the specified power. Note that the client can’t actually order a solo – but may be able to order its units in a way that causes one to occur.
arrangement = NOT (arrangement)
All of the available arrangements can have NOT placed in front of them to mean the opposite. Double negatives should not be used!
arrangement = NAR (arrangement)
All of the available arrangements can also have NAR placed in front of them. This represents the lack of an arrangement. To use the level 20 token, XDO, as an example, XDO (order) is an arrangement that order will be ordered. NOT (XDO (order)) is an arrangement that order will not be ordered. NAR (XDO (order)) is an arrangement that allows order to be ordered, or not.
NAR is most commonly used in order to undo a previous arrangement.
To respond to a message, one of the following can be sent:
reply = YES (press_message)
Accept the arrangement
reply = REJ (press_message)
Reject the arrangement
reply = BWX (press_message)
Refuse to answer. None of the sending power’s business.
reply = HUH (press_message)
The message proposal contains a token sequence which is too complicated for this client to understand – usually because the client is not able to handle all the tokens that are available for press at the current level. In this case, the token ERR should be inserted immediately before the first token which could not be understood.
The above responses should only be sent as a response to a received message. press_message should be identical to the received message.
press_message = CCL (press_message)
A press message which proposes an arrangement can be cancelled before the arrangement has been agreed, using a CCL message. This can also be used to cancel a YES response to a proposed arrangement, before all parties involved in the proposal have replied.
A CCL message which is sent after the arrangement has been agreed has no effect, and CCL may not be used to cancel a message which is not attempting to form an agreement.
press_message = FCT (arrangement)
arrangement is true.
This is generally used either to pass information, or to unilaterally override a previously made agreement. There are no defined replies to FCT, although of course, a FCT message may cause other statements or proposals to follow.
If the client sends a response of HUH, it should immediately follow it with a second message informing the other client as to what it can understand. This is done with:
press_message = TRY (tokens)
List all of the tokens which the client can process when received in the press_message part of a FRM message. Tokens should be a subset of PRP PCE ALY VSS DRW SLO NOT YES REJ BWX. In addition, the following tokens from higher levels may also be included if they can be processed by the client: XDO DMZ AND ORR SCD OCC INS QRY THK FCT IDK SUG WHT HOW EXP SRY FOR IFF THN ELS XOY YDO FRM FWD SND
The client does not need to list TRY or HUH in tokens, and should not send a HUH message in response to a TRY or HUH message.
A client which can not process Press (i.e. it is only designed to work at Level 0) should respond to any FRM message with:
SND (power) (HUH (ERR press_message))
SND (power) (TRY ())
Where power is the sending power, and press_message is the received message.
All tokens which can be processed by the client may be included in games of any level (so that the client can just have a fixed TRY message which the client sends if it doesn’t understand something). There is no requirement to remove higher level tokens from the TRY message in lower level games. The Server will remove all higher level tokens from the TRY message before passing it onto the receiving power, and may also reorder the tokens.
In level 20, we add two new forms for arrangement.
arrangement = XDO (order)
This is a arrangement for the given order to be ordered. order uses the same format as in the SUB command.
An XDO arrangement applies to the next turn in which the order type is valid – so the next movement turn for a HLD, MTO, SUP, CVY or CTO order, the next retreat turn for a RTO or DSB order, and the next adjustment turn for a BLD, REM or WVE order.
arrangement = DMZ (power power ...) (province province ...)
This is an arrangement for the listed powers to remove all units from, and not order to, support to, convoy to, retreat to, or build any units in any of the list of provinces. Eliminated powers must not be included in the power list. The arrangement is continuous (i.e. it isn’t just for the current turn).
Both of these are responded to using the responses in level 10.
Level 30 adds the ability to combine multiple arrangements.
arrangement = AND (arrangement) (arrangement) (arrangement) ...
These arrangements are grouped, and should be accepted or rejected as a group. This is usually used for arrangements such as “I support you and you support me”.
arrangement = ORR (arrangement) (arrangement) (arrangement) ...
These alternative arrangements are grouped. The client should accept or reject them as a group, and then use further press (if necessary) to decide which part of the arrangement is to actually occur. This is usually used for offers such as “I will make one of the following moves”.
ORR is logical inclusive-or. That is, doing more than one of the arrangements is not against the overall arrangements.
At level 30, AND and ORR must not be nested – they must not both appear in the same message, and neither of them is allowed to appear more than once. All AND and ORR offers must include at least two sub-offers. E.g. AND (arrangement) is not allowed.
Level 40 adds the ability to discuss who will gain which supply centres and provinces.
arrangement = SCD (power centre centre ...) (power centre centre ...) ...
The given supply centre distribution is arranged. This is typically used when an alliance is sharing out the centres of the powers they are allied against. Any centres not listed are not part of the division. Eliminated powers must not be included in the distribution of centres. The offer is a long term plan, it doesn’t necessarily indicate that the centres will be taken this turn.
arrangement = OCC (unit) (unit) ...
This is an arrangement for a power to place a particular unit in a particular location. unit is in the same format as for NOW. For instance PRP (OCC (ENG FLT BEL)). Alternatively, the token UNT may be used to represent any unit type. E.g. PRP (OCC (ENG UNT BEL)). The offer is a long term plan, it doesn’t necessarily indicate that the unit will be placed there this turn.
Level 50 allows AND and ORR to be nested. So the client can do the following:
PRP (ORR ((FRA AMY PAR) MTO PIC) (AND ((FRA AMY PAR) MTO BUR) ((GER AMY MUN) MTO BUR)))
It also adds a new token. CHO.
arrangement = CHO (minimum maximum) (arrangement) (arrangement) (arrangement) ...
minimum and maximum are numbers. It is an arrangement for a number of the arrangements between the minimum and maximum number specified. minimum and maximum will often be the same, in which case it means choose exactly that many.
For example:
CHO (2 2) (SCD (ENG NWY)) (SCD (ENG DEN)) (SCD (ENG SWE))
Choose two centres from Norway, Denmark and Sweden.
In Level 60, we add the ability to insist on an arrangement, and to ask a question.
press_message = INS (arrangement)
The syntax for INS is exactly the same as for PRP, and the available replies are also exactly the same. The only difference is that PRP should be seen as a suggestion, where as INS is much more forceful, and implies that relations between the two powers will be worsened if the arrangement is not accepted. If arrangement is something that the sending power can enforce on the board (e.g. an order for one of his own units), then the receiving power should expect it to happen whether he likes it or not.
press_message = QRY (arrangement)
The syntax for QRY is the same as for PRP and INS. QRY is asking a question – e.g. is there an alliance, rather than proposing – e.g. how about an alliance. QRY is responded to in exactly the same way as PRP and INS. However, the following extra responses are also available for QRY:
reply = THK (QRY (arrangement))
I think that arrangement is true.
reply = THK (NOT (QRY (arrangement)))
I think that arrangement is not true.
reply = FCT (QRY (arrangement))
arrangement is true.
reply = FCT (NOT (QRY (arrangement)))
arrangement is not true.
reply = IDK (QRY (arrangement))
I don’t know.
press_message = SUG (arrangement)
The syntax for SUG is the same as for QRY. SUG is suggesting that something is in the mutual interest of the party sending, and all parties receiving the message, but is not something they can directly influence. For instance, Italy may want to say to Austria that it is in their mutual interest for Russia to order to the Black Sea. Replies to SUG are the same as for PRP. However, the response is an indication of agreement or disagreement, rather than an indication as to whether arrangement will actually happen.
THK and FCT can also be used as a message in their own right, to pass information without first being queried for the information. FCT has already been introduced in level 10.
press_message = THK (arrangement)
I think arrangement is true.
No reply is expected to either of these.
Note that THK (QRY (arrangement)) and THK (arrangement) have exactly the same meaning, except that the former is the response to a query where as the latter is volunteered without being asked. The same applies to FCT (QRY (arrangement)) and FCT (arrangement).
In Level 70, we add the ability to ask for suggestions. Requests for suggestions come in two forms:
press_message = WHT (unit)
What should unit be ordered to do? This can either be for the sending or a receiving powers unit. In the former case, it is a request for a suggestion. In the latter case, it is a request for information.
WHT messages should be replied to using PRP, INS to propose or insist on a move (as if it was an initial proposal/insistence, rather than a response to a WHT), IDK (WHT (unit)) if the receiving power doesn’t have a suggestion, or with BWX (WHT (unit)) if the receiving power doesn’t want to tell.
press_message = HOW (province)
How do you think we should attack province. This should be responded to with PRP or INS to propose or insist on moves, or with REJ (HOW (province)) to indicate that the province should not be attacked, IDK (HOW (province)) if the receiving power doesn’t have a suggestion, or with BWX (HOW (province)) if the receiving power doesn’t want to tell.
press_message = HOW (power)
How do you think we should attack power. Responses are the same as for HOW (province). power must not be an eliminated power.
Level 80 adds the ability to accuse another power of going back on its word.
press_message = EXP (turn) (press_message)
press_message = EXP (turn) (reply)
Explain your moves in turn given press_message that you previously sent.
The standard replies can be used, including:
reply = YES (EXP (turn) (press_message))
reply = YES (EXP (turn) (reply))
Yes I know (no explanation given)
reply = REJ (EXP (turn) (press_message))
reply = REJ (EXP (turn) (reply))
I didn’t send press_message
reply = IDK (EXP (turn) (press_message))
reply = IDK (EXP (turn) (reply))
There is nothing to explain – they don’t conflict
In addition, the following is available.
reply = SRY (EXP (turn) (press_message))
reply = SRY (EXP (turn) (reply))
I’m sorry.
Especially after a YES or BWX message, it will be common for the next message to be INS (NOT (PCE (power power ...))).
Level 90 adds the ability to talk about the future. To do this, one command is added:
arrangement = FOR (turn) (arrangement)
arrangement = FOR ((start_turn) (end_turn)) (arrangement)
For the turn specified, or for all turns from start_turn to end_turn inclusive, arrangement applies. turn is of the form phase_year. The timing specified by FOR overrides any timing indicated by arrangement.
The arrangement parameter of the FOR must not include a further FOR, unless the arrangement contains a press_message (e.g. in SND), and the further FOR is inside that press_message.
Note that FOR and NOT must be ordered correctly to get the right meaning. FOR ((start_turn) (end_turn)) (NOT (arrangement)) means that arrangement is not true for any of the turns indicated, while NOT (FOR ((start_turn) (end_turn)) (arrangement)) means that arrangement is not true for at least one of the turns indicated.
Level 100 adds the ability to make use conditional operators.
press_message = IFF (condition) THN (press_message)
press_message = IFF (condition) THN (press_message) ELS (press_message)
If the condition is met then the THN part applies, otherwise the ELS part applies.
A condition takes the same format as an arrangement.
IFF is often used in conjunction with FOR. i.e. :
IFF (NOT (XDO ((RUS FLT (STP NCS)) BLD ))) THN (PRP(FOR (SPR 1902) (XDO ((ENG FLT NWY) SUP (RUS FLT GOB) MTO SWE)))) ELS (INS(FOR (SPR 1902) (XDO ((ENG FLT NWY) SUP (GER FLT DEN) MTO SWE))))
It is recommended that IFF statements are always worded so that the receiving power would prefer the THN part to the ELS part.
Level 110 adds the ability to trade in favours, and to become a puppet of another power.
arrangement = XOY (power) (power)
Power X owes power Y. The powers listed must not be eliminated powers.
The amount owed is indicated by the context. For instance, a client may ask for "You support me to X, and I owe you.". The amount owed is the value of the support. It's for when the client is asking for something now, and offering to return the favour later, not yet knowing how it will be returned.
arrangement = YDO (power) (unit) (unit) ...
The control of the listed units is given to power. If the owner of the units is the sending power then it is allowing the named power to decide the orders for those units (which he should do using PRP (XDO ...) ). The orders for the units must still be entered by the owning power. The power must not be an eliminated power.
Level 120 adds the ability to forward press from one power to another. This adds three extra commands to the message syntax:
arrangement = SND (power) (power power ...) (press_message)
arrangement = SND (power) (power power ...) (reply)
This is a request for the first power to send the message given. Eliminated powers must not be included in any part of the message.
arrangement = FWD (power power ...) (power) (power)
This is either an arrangement for any messages received from any of the powers in the first parameter to the power in the second parameter to be forwarded to the power in the third parameter. Eliminated powers must not be included in any part of the message. Powers should not appear twice in the message. The arrangement is continuous (i.e. it isn’t just for the current turn).
arrangement = BCC (power) (power power ...) (power)
This is exactly the same as FWD, except that the sending and receiving powers are now the first and third parameters. This is an arrangement to forward everything sent, rather than everything received.
arrangement = NOT (FWD (power power ...) (power) (power))
arrangement = NOT (BCC (power) (power power ...) (power))
This is cancels a previously agreed FWD or BCC arrangement.
press_message = FRM (power) (power power ...) (press_message)
press_message = FRM (power) (power power ...) (reply)
This is a message to inform a power of a message that has been sent or received. No response is required. Eliminated powers must not be included in any part of the message. There is of course no guarantee that the forwarded message is genuine.
Care should be taken to avoid message passing loops. In general, a client should not forward a message that already contains the segment (FRM (you) (power you are forwarding to) (press_message)).
Level 130 adds the ability to ask why a power thinks something. In response to a THK or FCT message, a client can reply with:
reply = WHY (THK (arrangement))
reply = WHY (FCT (arrangement))
This is a request for an explanation as to the reason why sender thinks the arrangement in the THK or FCT message is true. Available replies are BWX if the client don’t want to tell, REJ if the client wants to deny knowledge of the THK or FCT message, or another THK or FCT message to give further information. Additionally, a client can also give any other message which gives further information (most notably a FRM message received from another power). Finally, there is one new response available:
reply = POB (WHY (...))
The position on the board, or the previous moves, suggests/implies it. WHY can also be used in other contexts:
reply = WHY (SUG (arrangement))
Why do you think that would be good for us?
reply = WHY (PRP (arrangement)) reply = WHY (INS (arrangement))
Why are you proposing that?
Level 130 also adds some additional uses of IDK:
reply = IDK (PRP (arrangement))
reply = IDK (INS (arrangement))
I don't know whether I'll accept that. Throw in something else to make it worthwhile.
reply = IDK (SUG (arrangement))
I don't really know whether I desire that.
In Level 140, we add the ability to respond to a message by expressing the emotional state upon receiving the message. One of following can be sent:
reply = UHY(press_message)
Unhappy with the message
reply = HPY(press_message)
Happy with the message
reply = ANG(press_message)
Angry with the message
The above responses should only be sent as a response to a received message. press_message should be identical to the received message.
In Level 150, we add the ability to request or demand for an offer.
From Level 10, a power can propose an arrangement with press_message
press_message = PRP(arrangement)
To request an offer:
arrangement = ROF
Thus, to send a request for an offer to a power or multiple powers:
SND(power power…)(PRP(ROF))
Here, the list of powers (power power ...) who will receive the request.
Example, SND (GER AUS) (PRP(ROF)) , if any power is requesting Germany and Russia for an offer
Following level 60, a power can demand or Insist on an offer with INS token such as the following:
press_message = INS(ROF)
Example,SND (GER AUS) (INS(ROF))" , if any power insisting or demanding Germany and Austria for an offer
Level 160 adds the ability to specify a utility lower or upper bound for a power. This is intended for use with threats to show how much cooperation benefits the receiver over the threatened punishment.
arrangement = ULB (power float)
Utility lower bound of float for power.
arrangement = UUB (power float)
Utility upper bound of float for power.
Float is a floating point number in a format typically used by programming languages. It is currently parsed with the following regular expression: [-+]?((\d*\.\d+)|(\d+\.?))([Ee][+-]?\d+)?
Strategy Robot Note: We intend to use INS to indicate active punishment or reward (changing our move to enforce the utility bound). In contrast, PRP indicates that we predict the utility bound is correct without our active enforcement.
Example message sent from England to Germany:
IFF (XDO((GER AMY BER) MTO MUN)) THN (PRP (ULB (GER 0.8))) ELS (INS (UUB (GER 0.1)))
This is a threat from England to Germany that says if you move BER to MUN then I predict you will get at least 0.8 utility, but if you do anything else I will move to prevent you from getting more than 0.1 utility. In this case we are actively punishing Germany.
Example message sent from England to Germany:
IFF (XDO((GER AMY BER) MTO MUN)) THN (PRP (ULB (GER 0.8))) ELS (PRP (UUB (GER 0.3)))
This is a threat from England to Germany that says if you move BER to MUN then I predict you will get at least 0.8 utility, but if you do anything else I will predict you will get at most 0.3 utility. In this case we are not actively punishing or rewarding, we are just sharing the results of our game theory analysis.
This level allows natural language press. Both message and reply can be any string of ASCII characters.
The following is a complete alphabetical list of tokens specified in the Diplomacy AI Development Environment Syntax.
| Token | Token Type | Usage | Meaning |
|---|---|---|---|
| ADR | Province | Sea | Adriatic Sea |
| AEG | Province | Sea | Aegean Sea |
| ALB | Province | Coastal | Albania |
| ALY | Press | Ally | |
| AMY | Unit Type | Army | |
| AND | Press | Logical AND | |
| ANK | Province | Coastal Supply Centre | Ankara |
| AOA | Parameter | HLO | Any Orders Allowed |
| APU | Province | Coastal | Apulia |
| ARM | Province | Coastal | Armenia |
| AUS | Power | Austria | |
| AUT | Phase | Fall Retreats | |
| BAL | Province | Sea | Baltic Sea |
| BAR | Province | Sea | Barents Sea |
| BCC | Press | Request to Blind Carbon Copy | |
| BEL | Province | Coastal Supply Centre | Belgium |
| BER | Province | Coastal Supply Centre | Berlin |
| BLA | Province | Sea | Black Sea |
| BLD | Order | Build Phase | Build |
| BNC | Order Note | ORD | Move Bounced |
| BOH | Province | Inland | Bohemia |
| BPR | Order Note | THX | REMOVED |
| BRE | Province | Coastal Supply Centre | Brest |
| BTL | Parameter | HLO | Build Time Limit |
| BUD | Province | Inland Supply Centre | Budapest |
| BUL | Province | Bicoastal Supply Centre | Bulgaria |
| BUR | Province | Inland | Burgundy |
| BWX | Press | None of Your Business | |
| CCD | Command | Server to Client | Power in Civil Disorder |
| CCL | Press | Cancel | |
| CHO | Press | Choose | |
| CLY | Province | Coastal | Clyde |
| CON | Province | Coastal Supply Centre | Constantinople |
| CST | Order Note | THX | No Coast Specified |
| CTO | Order | Movement Phase | Move by Convoy to |
| CUT | Order Note | ORD | Support Cut |
| CVY | Order | Movement Phase | Convoy |
| DEN | Province | Coastal Supply Centre | Denmark |
| DMZ | Press | Demiliterised Zone | |
| DRW | Command / Press | Client <---> Server | Draw |
| DSB | Order | Retreat Phase | Disband |
| DSR | Order Note | ORD | Convoy Disrupted |
| EAS | Province | Sea | Eastern Mediterranean Sea |
| ECH | Province | Sea | English Channel |
| ECS | Coast | East Coast | |
| EDI | Province | Coastal Supply Centre | Edinburgh |
| ELS | Press | IFF | Else |
| ENG | Power | England | |
| ERR | Parameter | HUH | Error location |
| ESC | Order Note | THX | Not an Empty Supply Centre |
| EXP | Press | Explain | |
| FAL | Phase | Fall Movements | |
| FAR | Order Note | THX | Not Adjacent |
| FCT | Press | Fact | |
| FIN | Province | Coastal | Finland |
| FLD | Order Note | ORD | REMOVED |
| FLT | Unit Type | Fleet | |
| FOR | Press | For specified Turn | |
| FRA | Power | France | |
| FRM | Command / Press | Server to Client | Message From |
| FWD | Press | Request to Forward | |
| GAL | Province | Inland | Galecia |
| GAS | Province | Coastal | Gascony |
| GER | Power | Germany | |
| GOB | Province | Sea | Gulf of Bothnia |
| GOF | Command | Client to Server | Go Flag |
| GOL | Province | Sea | Gulf of Lyons |
| GRE | Province | Coastal Supply Centre | Greece |
| HEL | Province | Sea | Helgoland Bight |
| HLD | Order | Movement Phase | Hold |
| HLO | Command | Server to Client | Hello (Start of Game) |
| HOL | Province | Coastal Supply Centre | Holland |
| HOW | Press | How to attack | |
| HSC | Order Note | THX | Not a Home Supply Centre |
| HST | Command | Client to Server | History |
| HUH | Command / Press | Server to Client | Syntax Error / Not Understood |
| IAM | Command | Client to Server | I am |
| IDK | Press | I Don't Know | |
| IFF | Press | If | |
| INS | Press | Insist | |
| ION | Province | Sea | Ionian Sea |
| IRI | Province | Sea | Irish Sea |
| ITA | Power | Italy | |
| KIE | Province | Coastal Supply Centre | Kiel |
| LOD | Command | Server to Client | Load Game |
| LON | Province | Coastal Supply Centre | London |
| LVL | Parameter | HLO | Level (Language Level) |
| LVN | Province | Coastal | Livonia |
| LVP | Province | Coastal Supply Centre | Liverpool |
| MAO | Province | Sea | Mid Atlantic Ocean |
| MAP | Command | Server to Client | Map to be used for this game |
| MAR | Province | Coastal Supply Centre | Marseilles |
| MBV | Order Note | THX | Might Be Valid |
| MDF | Command | Client <---> Server | Map definition |
| MIS | Command | Server to Client | Missing Orders |
| MOS | Province | Inland Supply Centre | Moscow |
| MRT | Parameter | NOW | Must Retreat to |
| MTL | Parameter | HLO | Movement Time Limit |
| MTO | Order | Movement Phase | Move To |
| MUN | Province | Inland Supply Centre | Munich |
| NAF | Province | Coastal | North Africa |
| NAO | Province | Sea | North Atlantic Ocean |
| NAP | Province | Coastal Supply Centre | Naples |
| AR | Press | No Agreement | |
| NAS | Order Note | THX | Not At Sea |
| NCS | Coast | North Coast | |
| NMB | Order Note | THX | No More Builds Allowed |
| NME | Command | Client to Server | Name |
| NMR | Order Note | THX | No More Retreats Allowed |
| NOT | Command / Press | Client <---> Server | Logical NOT |
| NOW | Command | Client <---> Server | Current Position |
| NPB | Parameter | HLO | No Press During Builds |
| NPR | Parameter | HLO | No Press During Retreats |
| NRN | Order Note | THX | No Retreat Needed |
| NRS | Order Note | THX | Not the Right Season |
| NSC | Order Note | THX | Not a Supply Centre |
| NSF | Order Note | THX | No Such Fleet |
| NSO | Order Note | ORD | No Such Order |
| NSP | Order Note | THX | No Such Province |
| NSU | Order Note | THX | No Such Unit |
| NTH | Province | Sea | North Sea |
| NVR | Order Note | THX | Not a Valid Retreat |
| NWG | Province | Sea | Norwegian Sea |
| NWY | Province | Coastal Supply Centre | Norway |
| NYU | Order Note | THX | Not Your Unit |
| OBS | Command | Client to Server | Observer |
| OCC | Press | Occupy | |
| OFF | Command | Server to Client | Turn Off (Exit) |
| ORD | Command | Server to Client | Order Results |
| ORR | Press | Logical OR | |
| OUT | Command | Server to Client | Power is Eliminated |
| PAR | Province | Inland Supply Centre | Paris |
| PCE | Press | Peace | |
| PDA | Parameter | HLO | Partial Draws Allowed |
| PIC | Province | Coastal | Picardy |
| PIE | Province | Coastal | Piedmont |
| POB | Press | Position on Board | |
| POR | Province | Coastal Supply Centre | Portugal |
| PRN | Command | Server to Client | Parenthesis error |
| PRP | Press | Propose | |
| PRU | Province | Coastal | Prussia |
| PTL | Parameter | HLO | Press Time Limit |
| QRY | Press | Query | |
| REJ | Command / Press | Server to Client | Reject |
| REM | Order | Build Phase | Remove |
| RET | Order Note | ORD | Unit must retreat |
| ROM | Province | Coastal Supply Centre | Rome |
| RTL | Parameter | HLO | Retreat Time Limit |
| RTO | Order | Retreat Phase | Retreat to |
| RUH | Province | Inland | Ruhr |
| RUM | Province | Coastal Supply Centre | Rumania |
| RUS | Power | Russia | |
| SCD | Press | Supply Centre Distribution | |
| SCO | Command | Client <---> Server | Supply Centre Ownership |
| SCS | Coast | South Coast | |
| SER | Province | Inland Supply Centre | Serbia |
| SEV | Province | Coastal Supply Centre | Sevastopol |
| SIL | Province | Inland | Silesia |
| SKA | Province | Sea | Skaggerack |
| SLO | Command | Server to Client | Solo |
| SMR | Command | Server to Client | Summary |
| SMY | Province | Coastal Supply Centre | Smyrna |
| SND | Command / Press | Client to Server | Send Message |
| SPA | Province | Bicoastal Supply Centre | Spain |
| SPR | Phase | Spring Movement | |
| SRY | Press | Sorry | |
| STP | Province | Bicoastal Supply Centre | St Petersburg |
| SUB | Command | Client to Server | Submit Order |
| SUC | Order Note | ORD | Order Succeeds |
| SUG | Press | Suggest | |
| SUM | Phase | Spring Retreats | |
| SUP | Order | Movement Phase | Support |
| SVE | Command | Server to Client | Save Game |
| SWE | Province | Coastal Supply Centre | Sweden |
| SYR | Province | Coastal | Syria |
| THK | Press | Think | |
| THN | Press | IFF | Then |
| THX | Command | Server to Client | Thanks for the order |
| TME | Command | Client <---> Server | Time to Deadline |
| TRI | Province | Coastal Supply Centre | Trieste |
| TRY | Press | Try the following tokens | |
| TUN | Province | Coastal Supply Centre | Tunis |
| TUR | Power | Turkey | |
| TUS | Province | Coastal | Tuscany |
| TYR | Province | Inland | Tyrolia |
| TYS | Province | Sea | Tyrrhenian Sea |
| UKR | Province | Inland | Ukraine |
| UNO | Parameter | SCO | Unowned |
| UNT | Press | OCC | Unit |
| VEN | Province | Coastal Supply Centre | Venice |
| VIA | Order | Movement Phase | Move via |
| VIE | Province | Inland Supply Centre | Vienna |
| VSS | Press | ALY | Versus |
| WAL | Province | Coastal | Wales |
| WAR | Province | Inland Supply Centre | Warsaw |
| WES | Province | Sea | Western Mediterranean Sea |
| WHT | Press | What to do with | |
| WHY | Press | Why | |
| WIN | Phase | Fall Builds | |
| WVE | Order | Build Phase | Waive |
| XDO | Press | Moves to do | |
| XOY | Press | X owes Y | |
| YDO | Press | You provide the order for these units | |
| YES | Command / Press | Server to Client | Accept |
| YOR | Province | Coastal | Yorkshire |
| YSC | Order Note | THX | Not Your Supply Centre |
| integer | Parameter | Various | Used for years, number of builds, etc. |
This appendix lists the entire language in a more machine-oriented form, similar to BNF. The first two types, client_server_message and server_client_message are the complete messages that can be sent. They are then composed of tokens and other types. To read the table, the category in the first column can be replaced by any of the combinations in the third column. The language level in the second column indicates the minimum language level at which this substitution is allowed. OBS indicates any level including an Observer.
| Type | Level | Composition |
|---|---|---|
| client_server_message | OBS | NME ( string ) ( string ) |
| OBS | OBS | |
| OBS | IAM ( power ) ( number ) | |
| OBS | MAP | |
| OBS | MDF | |
| OBS | YES ( acknowledgable_command ) | |
| OBS | REJ ( acknowledgable_command ) | |
| OBS | NOW | |
| OBS | SCO | |
| OBS | HST ( turn ) | |
| OBS | TME ( number ) | |
| OBS | TME | |
| OBS | ADM ( string ) ( string ) | |
| OBS | PRN ( bad_bracketed_sequence ) | |
| OBS | HUH ( any_token_sequence ) | |
| 0 | HLO | |
| 0 | SUB ( order ) ( order ) ... | |
| 0 | SUB ( turn ) ( order ) ( order ) ... | |
| 0 | NOT ( negatable_command ) | |
| 0 | MIS | |
| 0 | GOF | |
| 0 | ORD | |
| 0 | DRW | |
| 10 | DRW ( power power_list ) | |
| 10 | send_message | |
| server_client_message | OBS | YES ( client_command ) |
| OBS | YES ( client_request ) | |
| OBS | REJ ( client_request ) | |
| OBS | REJ ( rejectable_client_command ) | |
| OBS | MAP ( string ) | |
| OBS | MDF ( power_list ) ( mdf_provinces ) ( mdf_adjacency_list ) | |
| OBS | HLO ( power ) ( number ) ( variant ) | |
| OBS | NOW ( turn ) ( unit_with_location_and_mrt ) ( unit_with_location_and_mrt ) ... | |
| OBS | SCO ( sco_entry ) ( sco_entry ) ... | |
| 0 | THX ( order ) ( order_note ) | |
| 0 | MIS ( unit_with_location_and_mrt ) ( unit_with_location_and_mrt ) ... | |
| 0 | MIS ( number ) | |
| OBS | ORD ( turn ) ( order ) ( compound_order_result ) | |
| 0 | SVE ( string ) | |
| 0 | LOD ( string ) | |
| OBS | OFF | |
| OBS | TME ( number ) | |
| OBS | PRN ( bad_bracketed_sequence ) | |
| OBS | HUH ( any_token_sequence ) | |
| OBS | CCD ( power ) | |
| OBS | NOT ( negated_server_message ) | |
| OBS | ADM ( string ) ( string ) | |
| OBS | SLO ( power ) | |
| OBS | DRW | |
| OBS | SMR ( turn ) ( power_summary ) ( power_summary ) ... | |
| 10 | DRW ( power power_list ) | |
| 10 | OUT ( power ) | |
| 10 | FRM ( power number ) ( power_list ) ( press_message ) | |
| 10 | FRM ( power number ) ( power_list ) ( reply ) | |
| acknowedgable_command | OBS | MAP ( string ) |
| OBS | SVE ( string ) | |
| any_token_sequence | OBS | Any sequence of tokens where the brackets all match correctly |
| bad_bracketed_sequence | OBS | A sequence of tokens where the bracketing is incorrect |
| coast | OBS | Any token from the Coast category |
| compound_order_result | OBS | order_note |
| OBS | order_result | |
| OBS | order_note RET | |
| OBS | order_result RET | |
| client_command | OBS | OBS |
| OBS | NOT ( TME ) | |
| client_request | OBS | NME ( string ) ( string ) |
| OBS | IAM ( power ) ( number ) | |
| 0 | NOT ( GOF ) | |
| 0 | GOF | |
| OBS | TME ( number ) | |
| OBS | DRW | |
| OBS | NOT ( negated_client_request ) | |
| 10 | DRW ( power power_list ) | |
| 10 | send_message | |
| explanation | 80 | EXP ( turn ) ( reply ) |
| future_offer | 10 | PCE ( power power_list ) |
| 10 | ALY ( power_list ) VSS ( power_list ) | |
| 10 | DRW | |
| 10 | SLO ( power ) | |
| 10 | NOT ( future_offer ) | |
| 20 | XDO ( order ) | |
| 20 | DMZ ( power_list ) ( province_list ) | |
| 40 | SCD ( sc_ownership_list ) ( sc_ownership_list ) ... | |
| 40 | OCC ( occ_unit_with_location ) ( occ_unit_with_location ) ... | |
| 50 | AND ( future_offer ) ( future_offer ) ... | |
| 50 | ORR ( future_offer ) ( future_offer ) ... | |
| 50 | CHO ( number number ) ( future_offer ) ( future_offer ) ... | |
| 110 | XOY ( power ) ( power ) | |
| 110 | YDO ( power ) ( unit_with_location ) ( unit_with_location ) ... | |
| 120 | SND ( power ) ( power_list ) ( press_message ) | |
| 120 | SND ( power ) ( power_list ) ( reply ) | |
| 120 | FWD ( power_list ) ( power ) ( power ) | |
| 120 | BCC ( power ) ( power_list ) ( power ) | |
| logical_operator | 30 | AND ( arrangement ) ( arrangement ) ... |
| 30 | ORR ( arrangement ) ( arrangement ) ... | |
| mdf_adjacencies | OBS | ( mdf_province_adjacencies ) ( mdf_province_adjacencies ) ... |
| mdf_centre_list | OBS | power province_list |
| OBS | UNO province_list | |
| OBS | ( power_list ) province_list | |
| mdf_coast | OBS | FLT coast |
| mdf_coast_adjacencies | OBS | unit_type mdf_province mdf_province ... |
| OBS | ( mdf_coast ) mdf_province mdf_province ... | |
| mdf_province | OBS | province |
| OBS | ( province_and_coast ) | |
| mdf_province_adjacencies | OBS | province ( mdf_coast_adjacencies ) ( mdf_coast_adjacencies ) ... |
| mdf_province_list | OBS | mdf_province mdf_province ... |
| mdf_provinces | OBS | ( mdf_supply_centres ) ( province_list ) |
| mdf_supply_centres | OBS | ( mdf_centre_list ) ( mdf_centre_list ) ... |
| negatable_command | OBS | SUB ( order ) |
| OBS | SUB | |
| OBS | GOF | |
| OBS | DRW | |
| OBS | DRW ( power power_list ) | |
| OBS | TME | |
| OBS | TME ( number ) | |
| negatable_query | 60 | QRY ( arrangement ) |
| 60 | NOT ( query ) | |
| negated_client_request | OBS | TME ( number ) |
| OBS | DRW | |
| 10 | DRW ( power power_list ) | |
| negated_server_message | OBS | CCD ( power ) |
| OBS | TME ( number ) | |
| number | OBS | Any token from the Number categories |
| arrangement | 10 | PCE ( power power_list ) |
| 10 | ALY ( power_list ) VSS ( power_list ) | |
| 10 | DRW | |
| 10 | SLO ( power ) | |
| 10 | NOT ( arrangement ) | |
| 10 | NAR ( arrangement ) | |
| 20 | XDO ( order ) | |
| 20 | DMZ ( power_list ) ( province_list ) | |
| 40 | SCD ( sc_ownership_list ) ( sc_ownership_list ) ... | |
| 40 | OCC ( occ_unit_with_location ) ( occ_unit_with_location ) ... | |
| 50 | AND ( arrangement ) ( arrangement ) ... | |
| 50 | ORR ( arrangement ) ( arrangement ) ... | |
| 50 | CHO ( number number ) ( arrangement ) ( arrangement ) ... | |
| 90 | FOR ( turn ) ( future_offer ) | |
| Unnamed: 0 | 90 | FOR ( period ) ( future_offer ) |
| 110 | XOY ( power ) ( power ) | |
| 110 | YDO ( power ) ( unit_with_location ) ( unit_with_location ) ... | |
| 120 | SND ( power ) ( power_list ) ( press_message ) | |
| 120 | SND ( power ) ( power_list ) ( reply ) | |
| 120 | FWD ( power_list ) ( power ) ( power ) | |
| 120 | BCC ( power ) ( power_list ) ( power ) | |
| order | OBS | ( unit_with_location ) HLD |
| OBS | ( unit_with_location ) MTO mdf_province | |
| OBS | ( unit_with_location ) SUP ( unit_with_location ) | |
| OBS | ( unit_with_location ) SUP ( unit_with_location ) MTO province | |
| OBS | ( unit_with_location ) CVY ( unit_with_location ) CTO province | |
| OBS | ( unit_with_location ) CTO province VIA ( province_list ) | |
| OBS | ( unit_with_location ) RTO mdf_province | |
| OBS | ( unit_with_location ) DSB | |
| OBS | ( unit_with_location ) BLD | |
| OBS | ( unit_with_location ) REM | |
| OBS | power WVE | |
| order_note | OBS | MBV |
| OBS | FAR | |
| OBS | NSP | |
| OBS | NSU | |
| OBS | NAS | |
| OBS | NSF | |
| OBS | NSA | |
| OBS | NYU | |
| OBS | NRN | |
| OBS | NVR | |
| OBS | YSC | |
| OBS | ESC | |
| OBS | HSC | |
| OBS | NSC | |
| OBS | CST | |
| OBS | NMB | |
| OBS | NMR | |
| OBS | NRS | |
| order_result | OBS | SUC |
| OBS | BNC | |
| OBS | CUT | |
| OBS | DSR | |
| OBS | NSO | |
| period | 90 | ( turn ) ( turn ) |
| power | OBS | Any token from the Power category |
| power_list | OBS | power power ... |
| power_summary | OBS | power ( string ) ( string ) number |
| OBS | power ( string ) ( string ) 0 number | |
| press_message | 10 | PRP ( arrangement ) |
| 10 | TRY ( try_parameters ) | |
| 10 | CCL ( press_message ) | |
| 30 | PRP ( logical_operator ) | |
| 60 | INS ( arrangement ) | |
| 60 | QRY ( arrangement ) | |
| 60 | SUG ( arrangement ) | |
| 60 | THK ( arrangement ) | |
| 610 | FCT ( arrangement ) | |
| 70 | WHT ( unit_with_location ) | |
| 70 | HOW ( province ) | |
| 70 | HOW ( power ) | |
| 80 | EXP ( turn ) ( reply ) | |
| 100 | IFF ( arrangement ) THN ( press_message ) | |
| 100 | IFF ( arrangement ) THN ( press_message ) ELS ( press_message ) | |
| 120 | FRM ( power number ) ( power_list ) ( press_message ) | |
| 120 | FRM ( power number ) ( power_list ) ( reply ) | |
| 8000 | string | |
| province | OBS | Any token from any of the Province categories |
| province_list | OBS | province province ... |
| province_and_coast | OBS | province coast |
| query | 60 | QRY ( arrangement ) |
| reply | 10 | YES ( press_message ) |
| 10 | REJ ( press_message ) | |
| 10 | BWX ( press_message ) | |
| 10 | HUH ( any_token_sequence ) | |
| 60 | THK ( negatable_query ) | |
| 60 | FCT ( negatable_query ) | |
| 60 | IDK ( query ) | |
| 80 | YES ( explanation ) | |
| 80 | REJ ( explanation ) | |
| 80 | IDK ( explanation ) | |
| 80 | SRY ( explanation ) | |
| 130 | WHY ( think_and_fact ) | |
| 130 | POB (why_sequence ) | |
| 130 | WHY ( SUG ( arrangement ) ) | |
| 130 | WHY ( PRP ( arrangement ) ) | |
| 130 | WHY ( INS ( arrangement ) ) | |
| 130 | IDK ( PRP ( arrangement ) ) | |
| 130 | IDK ( INS ( arrangement ) ) | |
| 130 | IDK ( SUG ( arrangement ) ) | |
| 10 | press_message | |
| rejectable_client_command | OBS | HLO |
| OBS | NOW | |
| OBS | SCO | |
| OBS | HST ( turn ) | |
| 0 | SUB ( order ) ( order ) ... | |
| OBS | ORD | |
| OBS | TME | |
| OBS | ADM ( string ) ( string ) | |
| sc_ownership_list | OBS | power province_list |
| OBS | UNO province_list | |
| sco_entry | OBS | power province_list |
| season | OBS | Any token from the Season category |
| send_message | 10 | SND ( power_list ) ( press_message ) |
| 10 | SND ( power_list ) ( reply ) | |
| 10 | SND ( turn ) ( power_list ) ( press_message ) | |
| 10 | SND ( turn ) ( power_list ) ( reply ) | |
| string | OBS | Sequence of tokens from the ASCII category |
| think_and_fact | 130 | THK ( arrangement ) |
| 130 | FCT ( arrangement ) | |
| try_parameters | 10 | |
| 10 | try_token try_token ... | |
| try_token (client to server) | 10 | PRP |
| 10 | PCE | |
| 10 | ALY | |
| 10 | VSS | |
| 10 | DRW | |
| 10 | SLO | |
| 10 | NOT | |
| 10 | ||
| 10 | YES | |
| 10 | REJ | |
| 10 | BWX | |
| 10 | CCL | |
| 10 | XDO | |
| 10 | DMZ | |
| 10 | AND | |
| 10 | ORR | |
| 10 | SCD | |
| 10 | OCC | |
| 10 | INS | |
| 10 | QRY | |
| 10 | THK | |
| 10 | FCT | |
| 10 | IDK | |
| 10 | SUG | |
| 10 | WHT | |
| 10 | HOW | |
| 10 | EXP | |
| 10 | SRY | |
| 10 | FOR | |
| 10 | IFF | |
| 10 | THN | |
| 10 | ELS | |
| 10 | XOY | |
| 10 | YDO | |
| 10 | FRM | |
| 10 | FWD | |
| 10 | SND | |
| 10 | WHY | |
| 10 | POB | |
| try_token (server to client) | 10 | PRP |
| 10 | PCE | |
| 10 | ALY | |
| 10 | VSS | |
| 10 | DRW | |
| 10 | SLO | |
| 10 | NOT | |
| 10 | ||
| 10 | YES | |
| 10 | REJ | |
| 10 | BWX | |
| 10 | CCL | |
| 20 | XDO | |
| 20 | DMZ | |
| 30 | AND | |
| 30 | ORR | |
| 40 | SCD | |
| 40 | OCC | |
| 60 | INS | |
| 60 | QRY | |
| 60 | THK | |
| 610 | FCT | |
| 60 | IDK | |
| 60 | SUG | |
| 70 | WHT | |
| 70 | HOW | |
| 80 | EXP | |
| 80 | SRY | |
| 90 | FOR | |
| 100 | IFF | |
| 100 | THN | |
| 100 | ELS | |
| 110 | XOY | |
| 110 | YDO | |
| 120 | FRM | |
| 120 | FWD | |
| 120 | SND | |
| 130 | WHY | |
| 130 | POB | |
| turn | OBS | season number |
| unit_type | OBS | Any token from the Unit category |
| unit_with_location | OBS | power unit_type province |
| OBS | power unit_type ( province_and_coast ) | |
| occ_unit_with_location | 50 | power unit_type province |
| 50 | power unit_type ( province_and_coast ) | |
| 50 | power UNT province | |
| unit_with_location_and_mrt | OBS | power unit_type province |
| OBS | power unit_type ( province_and_coast ) | |
| OBS | power unit_type province MRT ( mdf_province_list ) | |
| OBS | power unit_type ( province_and_coast ) MRT ( mdf_province_list ) | |
| variant | OBS | ( variant_option ) ( variant_option ) ... |
| variant_option | OBS | LVL number |
| OBS | MTL number | |
| OBS | RTL number | |
| OBS | BTL number | |
| OBS | AOA | |
| OBS | DSD | |
| 10 | PDA | |
| 10 | PTL number | |
| 10 | NPR | |
| 10 | NPB | |
| why_sequence | 130 | WHY ( think_and_fact ) |