The Room of Requirement, also called the Come and Go Room, is a secret room said to be created by Rowena Ravenclaw. It is able to transform into any type of room you need, whether it's a storage room, a training room, a library, or any other type of room you wish. The room is capable of "responding" to simple commands. However, there are a few rules to keep in mind: the room cannot generate any consumables, you cannot take out anything created by the room, and it cannot create any new knowledge. The room, however, is able to gather information from everything within itself and the near vicinity.
When summoned, a blank door will appear on the nearest wall or in front of the user, in case there are no walls nearby. The user or whoever is in front of the door must then walk in front of it three times while thinking of the kind of room they want. The door and the room are indestructible. When leaving the room, the user can leave from any location within a 50-meter radius. The user is also able to forcefully eject people who are still inside if they wish to do so.