ok so obviously map design would be a large factor in a game like this.
i think that for a map to work properly it needs to have multiple layers. 3-4 of them. this way you can have more than 4 doors in a small-ish room through hatches and other things. this is of particular importance in the main vault room / area guards can’t get in (which would be in the bottom layer), since if you only have 4 entrances to the vault then guards can just camp the entrances and the game becomes a stalemate. there would also be a few rooms next to the main vault room that the guards can’t access to introduce more entrances and more ways to get in
bottom layer would definitely be the vault. or top if we’re feeling like a pyramid instead of the cone but i’ll just say cone for now
middle layers would be various rooms that have various utilities and bonuses and ways to get through them and such. what you would normally expect from a “map”
top layer is the largest. it’s mostly the same as the middle layers, but there is many entrances at the borders (like up to 18 i think) that the thieves start at n shit. (teams would probably be grouped together)
it might be cool to have a mechanic that changes based upon how you broke into your entrance but that’s a bit too in-depth for this basic overview
guards would probably start in locations closer to the center of the layer below the top layer, or maybe just the center of the top layer if we’re feeling frisky today
also i think the thieves would periodically get the locations of their team broadcast to the whole game. otherwise you can say that they are using an invisibility device with limited functionality. there would be ways to catch thieves without, like, being in the same room as them when their location gets broadcast, but they would be harder than strategically moving the guards to surround the thieves or smth like that
it might be better to have them not always be invisible when they’re not broadcast. like, before they get broadcast they get a turn of invisbility or smth idk. and otherwise they’re able to be seen and need to manuever themselves around people properly
i think that “combat” wouldn’t really work in a game like this, at least thieves vs guards. the thieves should be actively avoiding engaging with the guards. i would think that if you get “caught” by guard(s) then you would instantly die unless you can quickly get away somehow; but there would be no odds of “death” in a given moment inbetween 0% and 100%.
thieves vs thieves is Plausible but it needs to be simple.
in endgame incapacitated thieves would return as backup near their initial entrance. if guards can get incapacitated in any way (not certain if this is possible in the first place but) they return after like 3 turns in the vault as SWAT teams or something idk. i just think that “dead” people should return in endgame to help their team