Doom Tower Secret Rooms

Secret Rooms are special challenge rooms in The Doom Tower that have certain champion requirements to enter.  Below you can see what those requirements are for each difficulty on each rotation.  These rooms are designed to make you use champions you may not normally use and help you expand you roster of champions.

To enter a Secret Room, you must have a silver key.  The key is only consumed when you complete the floor, enabling you to attempt different strategies if you are struggling on a specific room.  Once you complete the room, you will receive 2 silver keys and 2-3 champion fragments.  You receive epic champions fragments from normal and legendary from hard.