Roaring Furnace

If multiple effects modify your hand size, apply them in timestamp order. For example, if you unlock Steaming Sauna and then put Null Profusion (an enchantment that says your maximum hand size is two) onto the battlefield, your maximum hand size would be two. However, if Null Profusion entered first and then you unlocked Steaming Sauna, you would have no maximum hand size.

While in any zone other than the stack or the battlefield, a Room card's characteristics are a combination of its two doors. For example, Bottomless Pool // Locker Room has a mana value of 6 while it's in your library. If an effect allows you to search your library for a card with mana value 4 or less, you can't find Bottomless Pool // Locker Room.

If a spell or ability would create a copy of a Room spell on the stack, the copy retains the choice of which door was cast but also retains the full characteristics of the spell. The characteristics of the door that wasn't cast are still ignored while the copy is on the stack, and when the copy resolves, the token it becomes will enter with the appropriate door unlocked.