ToME: the Tales of Maj'Eyal

Obviously you don't get every fixdart in every game, but is the list of fixdarts that can be dropped in a given game not the same as the list of all fixdarts, and different between games? Asking because the list of fixdarts you can generate in debug mode differs between games, which seems very silly unless possible drops are determined at the start

The debug item creation varies depending on what area you're in; some items are east-only, for example.

Yup. You can get any artifact in any run, at least in a theoretical sense, so far as I'm aware. If you had far more time than sanity you could sit down and farm up just about every single fixed artifact in the game. Not all of them (without addons, anyway), 'cause there's things like the potion quest or that cursed thing, but pretty close to it. The create item debug menu option's just a little... fiddly, for lack of a better word.

There's just quite a few artifacts, and randarts to fill in for them besides, so in a normal (in terms of play, not difficulty) vanilla run you're just not going to see them all unless something freakishly improbable happens item drop wise.

... certain addons make it a bit more likely (mostly the ones like multi-class challenge or randboss rando, that can flood the game with boss mobs), but it's not going to happen in the base game without going very, very far out of your way.