Doors have existed in the game since the first day or two. There just were never many doors. The player could find random keys lying around, but barely anything to ever unlock. Let alone anything useful to unlock. That has now changed, because the game spawns doors starting at about the fifth room in.
Since everything in the game is generated, the game generates doors at random. Each room after the fifth room has a 50% chance of a door blocking your exit, but then that rate keeps going up, until eventually it’s every door is locked. This prevents the player from just running through rooms. Now the player has two ways to obtain keys. Either find one randomly from a shinny beacon on a shelf, or from a wanderer. If there is a locked door in a room, then somewhere in that room is a wanderer with a key.
Defeating wanderers gives the player a chance for a key. The more wanderers in the room, the less of a chance to get a key from a defeated wanderer. The final wanderer will always have a key, if a previous wanderer did not have one. The random chance at a key is necessary, and the chance of finding a key can be increased with abilities. For every level 10 Key Finder ability is an extra 10%. With four ability slots, that could be a 40% extra chance to find a key. Assuming the player can get 4 level 10 Key Finder abilities.
With that said, since it’s been so long into this project that a key has been required, the notification about requiring a key was glitched and stuck at the top left of the room rather than the center of the screen. There were a lot of issues with picking up such an old project to work on, but they’re all getting resolved.