A Treasure Room, or Item Room, is guaranteed to appear on all floors from Basement/Cellar 1 to Depths/Necropolis 2. A Treasure Room can be identified by the gold edges of the door. When the current floor is under the effect of Curse of the Labyrinth, there will be two treasure rooms on the floor.
Treasure Rooms do not require a key to open on the first floor of any run, even under the effect of Curse of the Labyrinth. In contrast, in the original Binding of Isaac, XL floors had two treasure rooms which both required a key.
Treasure Rooms will always contain one item from the Treasure Room pool, and never contain enemies. However, they may contain pots or skulls, which have a chance to spawn enemies when broken.
Treasure Rooms never border more than a single regular room, but there may be a Secret Room adjacent to it. More testing is necessary to determine if a Super Secret Room can border a Treasure Room.
Boss Challenge Room
Super Secret Room
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