These rooms wouldn’t have doors. The only way to notice them would be to spot inconsistencies in the interior layout. You might think at one point “This room is oddly small, considering it shares a wall with the previous room. It doesn’t add up.” Or perhaps you’d get a hint that there’s a hidden room if you’d hear noises coming from there. You would need a tool to break the wall if you’d want access.
Alternatively, add (un-disarmable) trap plates in the mansion, and stepping on them would open a nearby secret room by removing a single wall tile. (keeping in mind to add exceptions in case of various destruction scenarios, where the trap plate or the door gets destroyed). Low Perception characters might trigger these by accident.
Alternatively. cover the room entrance with a line of bookshelves, and you’d have to drag away a bookshelf to reveal the entrance. In case monsters are placed inside the secret rooms, monsters might break through the bookshelves, potentially catching a player off-guard. Also add more bookshelves in mansions, too.
It’s an open question what these rooms should contain. Rare books? Stashes of old weapons? Jewelry? Art, even? (Although the game doesn’t have paintings, does it?) Skeletal remains and spider webs? Old maps, marking the location of a treasure or a secret temple maybe? Messages that give hints that there are further underground levels in the mansion, and the downstairs into them can be revealed if one knows which piece of furniture to displace?
I sense potential for something lovecraftian here…
Of course, hidden rooms could be a part of other buildings as well. Homes, cathedrals… any others?
Hidden stairways would be much more difficult to find. You could make the hidden area’s a lot more intricate that way. And maybe some mansions could get regular basements too.
And we could have underground mansions with an elevator leading to a shack surrounded with fences and a pit full of dead women in red dresses! And undead women in red dresses! And blackjack!
Either place furniture on top of it to hide it. Or make it something like a landmine. High perception and being next to it will make it likely to find. A hidden metal or stone door perhaps disguised as wooden walls. May require a lockpick or electrohack(or just explosives) to get through.
Just as an example and a concept, one would ideally “bury” such small rooms deeper in the mansion interior. Ask yourselves if you’d ever notice that in the game if no one told you to look for it, or even if you knew to look for it. Of course not every mansion would have a hidden room. Some might even have multiple.
I guess it’s possible these mansion layouts would have to be drawn manually, in case they can’t be made to work with random generation algorithms.
and there is one building with hidden room anyway cabin in forest if you cant find it count windows inside and outside of course not every cabin have hidden room
Put a piece of furniture on top of it. I found a staircase in a house once because I moved a desk. 