Challenge rooms are areas where Cordy can obtain an item from a chest. However, in order to get her reward, Cordy must overcome the trial within the room. There is always no more than one challenge room per floor.
Depending on the type of challenge, Challenge rooms can be sorted into 3 categories:
1. Gauntlets Edit
The chest is usually located on the other side (long rooms) or in the center (large rooms), but in order to get it, the player must dodge oncoming projectiles and hazards. After which they have to make it back to the door.
2. Time Trials Edit
The player has 20 seconds to reach the chest and open it, or it will permanently vanish. However, in order to get to it the player must navigate around obstacles or find their way through a maze.
3. Survival Arenas Edit
The player must survive in the room with multiple hazards and/or enemies for 20 seconds in order to unlock the chest.
While Cat rooms can also be considered challenge rooms and will give Cordy an item, they appear independent from normal challenge rooms, as they require you to defeat all of the enemies inside, rather than simply survive. Also they can appear on same floor with challenge rooms.
Time-based challenge rooms will be locked until the chest is opened, or until it disappears.
Time Trial rooms, and Survival rooms will be cleared of enemies and projectiles after the chest is opened. However any props or hazards in the room will remain there, unless the player was playing a maze version of the Time Trial challenge.
The player can often use prop-breaking attacks on Time Trial rooms to "cheat the system", and reach the chest without navigating the challenge.