Part 37

Learn about Treasure Rooms, Shops, Boss Rooms, Secret Rooms, Challenge Rooms, and Mini-Boss Rooms in The Binding of Isaac: Rebirth.

Treasure Room:

Treasure Rooms are marked with a gold crown icon on the (minimap (the small circular map in the bottom-left corner of your screen)) (a small map displayed on the HUD (heads-up display — the on-screen icons showing health, ammo and the minimap)). The doorway connects to a general room and is outlined with gold and sometimes locked. A locked treasure room door cannot be blown up with a bomb. The treasure room never contains enemies, but always contains one item, most commonly a recharge item. It will also contain a couple of tiles of (terrain) (environmental elements like rocks or fires), most often a fire or poo. These rooms appear once on every floor, except on The Womb 1 and 2 floors, where they don't appear at all.

Shop:

Shops are denoted on the (minimap) by a penny icon. The doorway to a shop is always locked. Locked shop doors cannot be blown up with bombs. These rooms always connect to a general room and are found on every floor except the Womb 1 and 2 where they don't appear at all. Unlocking the door is used as a form of payment to enter the shop, so if you doubt you're going to buy an item from the shop and you only have a few keys, don't waste them opening the door to the room. Inside you'll find some kind of gruesome static corpse and three items with their prices listed below. To buy the item, simply walk on it; you'll pay the money and get the item. If you don't have enough money to buy the item, nothing happens. Items with red prices mean that the item is half price (all items except for tarot cards, pills and general pickups round prices down, while all of the exceptions are rounded up). The room only ever contains a small amount of terrain.

Boss Room:

Boss Rooms are found on every floor and are marked on the (minimap) by a large skull. The room is always connected to a general room and the doorway is the same dark grey of a (challenge room) (a room with specific combat objectives) but displays a skull above it in place of two crossed swords. Upon entering, the boss is introduced and then the battle commences. The door leading out of the room is closed until the battle is over (and they can't be destroyed with a bomb, so you can't escape). The room may or may not contain terrain and if it does, it will often be terrain specific to the boss. When the boss is killed a health reward is given and if there are any other enemies still alive, they must be killed before you're given your item reward, the (trapdoor) (an exit leading to the next floor) is revealed, the entrance door is reopened and the (Devil Room) (a special room that can appear after defeating a boss) appears (if you've taken little damage over the course of the entire floor). The item appears on a rock pedestal at the lower central part of the floor. The (trapdoor), that when moved onto leads to the next floor, appears at the upper central part of the floor. If the Devil Room appears, it appears where normal doorways are found.

Secret Room:

There is one secret room on every floor. It is marked with a question mark icon on the (minimap). The secret room is not revealed unless you are aided by an item or the secret entrance is opened by a bomb explosion or equivalent. Inside is usually either 3-9 pennies (one or more are sometimes nickles), a slot machine or an item. To open the entrance to a secret room, you must place a bomb where the door would normally be and let it explode. When an entrance is revealed (with the use of a bomb or item), a short sound file plays. The art style of the room is independent of what floor you're on. The room is almost completely empty besides the reward, with a corpse and only a few tiles of terrain present. Without the use of items, the only entrance present when you enter the room is the door you just came through, but others can be created with the aid of bombs if there is a room on the other side of the relevant wall. When you leave the secret room, the entrance closes although the location of the secret room is still shown on the (minimap) and you can reopen the entrance with another bomb. The doorways that lead to the secret room look more like caves. Secret Rooms almost never contain combat, although sometimes the (mini-boss) (a tougher enemy that appears before the main boss), Greed, can be spawned in the room (as punishment for your 'greed' for entering a secret room for a reward).

Challenge Room:

Challenge Rooms will be closed unless you have either full health or a lot of it. It is marked by two crossed swords on the (minimap). The doorway connects to a general room and is outlined with dark grey and displays two crossed swords above it. Contains one chest or locked golden chest that when opened will close the exit door (this cannot be blown up to escape) and a number of the same enemies will be spawned. Monsters come in waves or 'rounds'. Once the first lot of enemies are dealt with, a second lot, different to the first, will be spawned. Once these are killed, a third lot is spawned, different from the enemies before. The rounds commonly progress in difficulty, although this is not always the case. Once all three waves are killed, some form of reward spawns in the centre of the room. These rooms always lack terrain and have their own art style no matter what area you are in.

Mini-Boss Room:

These rooms contain a random (mini-boss). They can be found on any floor. They are not revealed as Mini-Boss rooms until you have entered the room and it's too late to react. Doorways look like the regular doorways that connect general rooms and this room is always connected to a general room. Upon entry, the (mini-boss) is introduced, the doors close and you fight. You can blow up closed doorways with bombs if you wish to escape. There can be a total lack of terrain in these rooms, as well as special terrain that is designed to suit the boss (the most notable being Wrath's (mini-boss) room). Upon winning, a reward is dropped and the doors reopen.