Seventy-Fifteen, Kurgstown. The challenge is survival. And loot, of course; have to have loot. But mainly survival. Every day you live is another day's adventure, another day's risk, and another day's funerals, for the ones who didn't make it. You've managed to reach adulthood, which probably puts your own lifespan into the 75th percentile; but now your training really begins, with magical and mundane life-and-death survival techniques. Good luck.
Despite the constant risks, you feel pretty good about your chances in life right now; after all, you got this far, right? You even have a few friends, and friends not only help your survival, they make looting oh! so much more gratifying. That fancy staff? Give it to the wizard. Ooh, full plate armor, only one way to find out if it's cursed or not! Some day, perhaps, you hope not too soon, it'll be time to face the Dragon, and you want to be ready...
Your first character starts at level 1. Use "roll stats" once and distribute the scores as you please. Yes, this means you're not as powerful as you might be, and there's going to be some variation in the scores. I know.
When (not if!) your first character dies, you may create a new character with half as many levels, rounded up. So if your character dies at level 7, you start a new one (of the same class or different) and immediately level to 4.
Unsurprisingly, it's the year 7015 of the current calendar. Months, weeks, and days are not named; time is simply counted in years since the dragon ascended to power. Within each year, days are numbered sequentially, with no intermediate divisions. Our story begins on Day 73 of this year; each session will generally advance time by one day, and time usually will not pass between sessions.
There are no permanent shops with regular inventory. Anyone who tried to run one would probably die poor, but people who adventure die rich. There is, however, an extensive and highly liquid market for weapons and armor of all types; in fact, you might even say that the value of the gold piece is defined in terms of weapons, rather than the other way around. All mundane and masterwork weapons and armor (including shields) can be purchased at DMG prices, and can be sold for the same (not halved). Basic enchantments on non-exotic weapons are also readily available. Everything else is probably available too, but subject to a DM's percentile roll, the goal for which depends on the level of enchantment and the specificity thereof (it's easier to get "any elemental enchantment" than "flaming burst"). Availability rolls may be retried daily.
Due to the near-perfect liquidity of weapons and armor, none will be given in loot - it's assumed that you sell them and get what you need. Consumables (potions/oils/scrolls/wands/staves) and rods/rings/wondrous items are far less available on the market, but can be found in loot.
In lieu of the regular starting package, players start with one +1 weapon of any design. If starting above level 1, the item is enchanted to that level or equivalent. Mundane goods listed in the PHB for less than 10gp are presumed to be available at no cost, as long as you don't mind that they were ripped off somebody's corpse a few days ago, and will probably get ripped off yours before long. (NOTE: This does not apply to services, since it's hard to rip a day's use of a hireling off somebody's corpse.)
Every day, and sometimes more than once a day, you'll be faced with a combat challenge. Battles against these 'Umbrals' is every bit as tough as battles against more solid foes would be, plus they're impossible to bluff or feint. All umbrals are mythical beings, completely fictional, and any resemblance to real person, alive or dead, is purely coincidental. Especially, they are most definitely NOT the ghosts of the deceased, and I have no idea why you would think that they might be. Anyway, they have nice loot, so if you can survive the battle, you'll be better off. Strangely, the battles seem to be always just a bit harder than you'd normally be able to manage - not enough to be overwhelming, but just hard enough that you're tempted to stay and fight, and probably die.
Expect to die and reroll at least once. No punches will be pulled. When you are dead, you are probably dead-dead, unless someone in the party has a Raise Dead spell; NPC spellcasters are not generally available.
At any time, you can challenge the dragon itself. The fight will be the party against the dragon, to the death. There is no retreating. Planar travel is prevented. If you fail, you ALL will die.
After every victory against an Umbral, you earn the right to ask one simple question about the dragon. It must be something that can be explained IC, so you can't ask its CR, but can ask about its age category (for instance). Answers are guaranteed to be truthful and accurate, but may be limited to what is known to a minor deity - since that's effectively what you're inquiring of. You may retain this information across death, and share it among the party. The question must be one of simple fact - you cannot request advice, for instance - and one victory entitles you to just one simple answer, not a whole book. Beyond that, it's basically up to you.