Each of the players in your session starts in their House, a building dedicated to sheltering them from the outside world. This is a very poetic way of describing a house. You know what a house is.
However, in Incrementality Matrix, houses behave a little differently from usual, especially after you Enter. Your House protects and empowers you in a more literal sense than it does in the normal world.
Your house is made up of House Features--various bits and pieces that provide useful mechanical benefits. Things that don't provide a mechanical benefit usually aren't House Features, but they still exist--it's safe to assume you have somewhere to make food and somewhere to take a nap, for instance. You also always have some kind of computing device available for running the house-editing interface, although the GM may rule that extenuating circumstances make it hard to reach or unavailable.
House Features are created using Build Grist and Strife Grist; the minimum amount of Grist you need to spend is dependent on your Homelevation Level.
If you're familiar with Homestuck's setting, you may wonder why the rules here allow you to create House Features for yourself whenever you want, rather than relying on a fellow player. The short version is, making you roleplay out every single new thing added to your House would be time-consuming and annoying, so the rules assume that most or all of it happens offscreen (which is how it happens in Homestuck). If you still want to roleplay interactions between you and your server player, go ahead--you might even earn Role Proficiency for it if it's particularly funny, heartwarming, or character-developing.
Most of the House Features you make will be Custom House Features--representing the various things that you create to enhance your House. These give you bonuses to your Base Stats and/or your Derived Stats, depending on whether you spend Strife Grist, Build Grist, or both.
The base cost of adding a custom House Feature is equal to 10 Build Grist times your Homelevation Level. In other words, at each new Homelevation Level, your House Features cost a little more, because you have to build around existing things and make sure everything's at least sort-of supported. Any grist you spend on top of this adds benefits; you can spend up to 100 Grist of each type on a House Feature.
House Features can add to your Base Stats, to one Derived Stat (except your Classpect Score), or both.
A House Feature can add to one Derived Stat at a time. For each 10 Build Grist you spend beyond the base cost, you add +3 to the Derived Stat you chose for this House Feature.
House Features cannot improve your Classpect Score; your Classpect is an unknowable force that cannot be directly trained.
A House Feature can also add to your Base Stats, and can add to multiple Base Stats at a time. For each 10 of a single type of Strife Grist you add, you add +2 to the Base Stat that Grist is associated with.
Some House Features are predefined and carry specific mechanical benefits. These are called Special House Features.
Grist costs for Special House Features are static; you can't pump more grist into a Special House Feature to make it better. However, the cost of a Special House Feature is still affected by your Homelevation Level. To get the actual cost of a Special House Feature, multiply its base cost by your Homelevation Level.
Special House Features can cost Build Grist, Strife Grist, or both. If a Special House Feature costs Strife Grist, you must spend only one type of Strife Grist to build it--but you can use any one kind of Strife Grist. (This means you don't have to worry about forgetting to add Shale Grist to your Land.)
Since your Homelevation Level starts at zero, your first 3 House Features--the Cruxtruder, Totem Lathe, and Alchemiter--are free. These are placed during Entry.
If you don't place those 3 machines at the start of the game, your character will be softlocked--stuck without the ability to Enter. This usually means they'll die due to an inconveniently-placed meteor. You should probably follow the Entry instructions.
Some Special House Features have a Prerequisite. You cannot build these House Features until you have all of the Prerequisites; they simply don't appear in your Phernalia Registry until then.
Base Cost: 0
The Cruxtruder enables you to create Cruxite Dowels, and is one of the four machines used for Alchemy (and one of the three machines used for Entry).
Without a Cruxtruder, you cannot begin Alchemizing new things--or making copies of existing items. Cruxite Dowels are a crucial step in the Alchemy process.
Furthermore, upon placing your Cruxtruder, you'll gain a Kernelsprite. Check the section on Entry for more details about what this does.
Base Cost: 0
The Totem Lathe carves Dowels into various curves for use in the Alchemiter. It is one of the four machines used for Alchemy (and one of the three machines used for Entry).
Technically, Alchemy can be performed with just the Totem Lathe and not the Punch Designix. However, this requires you to find pre-punched Captchalogue Cards, which generally aren't available. Unless you somehow got captchalogue cards from your future self, or something like that, in which case why didn't you just give yourself the cool stuff directly?
Base Cost: 0
The Alchemiter is the final step in Alchemy, enabling you to turn carved Cruxite Dowels into finished items. It is one of the four machines used for Alchemy (and one of the three machines used for Entry).
Without an Alchemiter, you cannot make items from Grist at all, regardless of how many carved dowels you have. You should probably avoid breaking this thing.
Base Cost: 4 Strife Grist Prerequisite: Build a Cruxtruder, Totem Lathe, and Alchemiter.
The Punch Designix enables you to punch Captchalogue Cards with the data used by the Totem Lathe, letting you carve new totems and enabling Alchemy. It is one of the four machines used for Alchemy, but it is not needed for Entry.
You can perform Alchemy by either double-punching a card in the Punch Designix, or by sticking two punched cards into the Totem Lathe's slot, but either way you need the Punch Designix or a selection of punched cards in order to get started.
Base Cost: 1 Build Grist
It keeps happening! Stairs are frustratingly dangerous, especially since they don't come with guardrails and there's no good way to add guardrails--this game's not OSHA compliant. However, if you need to ascend rapidly, they're your best friend.
Stairs function as a quick and cheap way to increase your Homelevation Level. They offer no mechanical advantages whatsoever, but their extremely low Base Cost makes them significantly more cost-effective than Custom House Features...if you only care about increasing your Homelevation Level. Beware--since the cost of House Features increases with your Homelevation Level, building too many stairs early on can make adding better House Features harder than it needs to be.
Base Cost: 80 Strife Grist, 350 Build Grist Prerequisite: Reach a Gate.
Supposedly, this was added as a patch to make SBURB more like a certain other home-building, adventure-having, glitchy-as-heck game. Which is weird, because that game doesn't even have Transportalizers, normally--they're added by a mod. Don't think too hard about it.
You can use a Transportalizer to travel to any Transportalizer that you or another party member knows about. This is because Transportalizers have a unique code associated with them, and if you can copy that code, you can target the Transportalizer it belongs to. The GM may even hide Transportalizer codes around your Land, but be wary of Transportalizing to someplace you don't know anything about…
Base Cost: 100 Build Grist Prerequisite: Grind at least once.
This device does some metaphysical mumbo-jumbo to turn Grist from an abstract concept into a form of transferable data, which can then be sent to other players and turned into Grist again (assuming they already have Grist of that type). But how come you can't just copy Grist? If you can turn matter into energy, and energy back into matter, what's stopping you from just generating infinite matter from energy? Does the concept of conservation of mass even apply to Grist at all? Stop asking so many questions, we have a game to play.
In order to send Grist to someone else, they have to already have some Grist of the type you want to send. If you try to send Grist of a type that they don't have, you'll get an ERR_PERMISSION_DENIED and an imp will spontaneously appear on top of your GristTorrent server. It's not really a big deal, imps stop being a threat pretty quickly, it's just kind of annoying.
Base Cost: 500 Build Grist Prerequisite: Build the Punch Designix.
The Jumper Block enables you to enhance the Alchemiter using punched Captchalogue Cards. Most of the time this doesn't do much, but building the Alchemiter Jumper Block does make Alchemy slightly cheaper, and also enables a bunch of other upgrades further down the line.
Once you have the Jumper Block, you may subtract your Alcheminsignia Rank from the final cost of any Alchemy Items you create. You only do this once, no matter how many types of Grist are on the item. You may choose which Grist type(s) to discount.
Base Cost: 5,000 Build Grist Prerequisite: Build the Alchemiter Jumper Block.
The Holopad simply displays one item based on the punched card inserted into it. However, when combined with the Alchemiter via the Jumper Block, it previews the item you're going to create, massively simplifying the process of making new items.
Once you have the Holopad, you may subtract your Homelevation Level from the final cost of any Alchemy Items you create.
Base Cost: 30,000 Build Grist Prerequisite: Build the Punch Designix.
The Intellibeam Laserstation uses a series of extremely complex optical scanning devices to make otherwise-incomprehensible Captchalogue codes readable, producing punched cards that violate basic laws of physics to store more information than should be possible with the punch-card mechanism. One theory as to how it does this is that the punched cards produced by the Laserstation are in fact fractal, with each edge of a punched hole containing a tiny row of tiny punched holes, each of which are in turn lined with even tinier punched holes. This is very silly.
Once you have the Intellibeam Laserstation, you may subtract your Puzzle Score's Scale from the final cost of any Alchemy Items you create. You may also create copies of items such as the SBURB Game Discs which are normally uncopiable.
Base Cost: 25,000 Build Grist, 25,000 Strife Grist Prerequisite: Build the GristTorrent Server.
This massive device uses extremely powerful particle beams--powered by your House's paradoxical near-infinite supply of electricity--to analyze the Grist costs of punched cards. With knowledge comes power--better understanding of Grist composition means more efficient use of Grist.
Once you have the SGM, you may subtract the number of Grist types in an Alchemy item's recipe, times your Alcheminsignia Rank, from the final cost of that Alchemy item. (For example, if you have Alcheminsignia Rank 5 and you have 5 types of Grist in an item, you subtract 25 from the final cost.)
Base Cost: 40,000 Build Grist Prerequisite: Find an Ectobiology Lab.
All the power of Ectobiology, in the comfort of your own House!
You may use Ectobiological Equipment to do Ectobiology without having to worry about being attacked while you're doing it.
Base Cost: 0 Prerequisite: Retrieve your Denizen's Grist Hoard.
This device plays a key role in the final steps of your journey. Unfortunately, it is so large--and so heavily integrated into the structure of your House--that you cannot build any new House Features once you've added it.
Seriously. Building this means you are locked out of building new House Features. Make sure you're ready for the final stages of the game before you build this device.
Base Cost: 5 Build Grist
Despite the name, this thing doesn't increase your Homelevation Level any faster than anything else. It's handy for getting around, though.
For each Home Elevator you've built, you can reduce the base cost of new Custom House Features by 2. This subtraction happens after you multiply the cost by your Homelevation Level.