Weapons are used against monsters - such as ghosts and vampires - that sometimes appear when new rooms are created. Loot consists of badges that enhance various combat statistics and provide permanent health upgrades and new weapons. The larger the room, the more loot-bearing chests it contains, and the more chests a room has, the better the loot each new chest is likely to contain. These rooms can be placed anywhere on the current floor, but placing them adjacent to a room of a similar color (each room's color is the same color as the shirt of the avatar from whom it was received) will connect the rooms, creating one larger room. Each Mii avatar players encounter via the 3DS StreetPass feature represents a room between one and five blocks in size.
Each floor begins at the top of a stairwell, but rooms don't exist until the player places them.
MONSTER MANOR uses the player's custom Mii avatar to explore a spooky old house with dozens of floors, scores of monsters, and loads of loot to find and collect.