An Item Room is a room in The Binding of Isaac: Rebirth. It is a room where a player can find one Collectible (at this point). It is marked by a golden crown on the Map and the door is also golden.
An Item Room will always contain one free Collectible, Active or Passive, on an Item Pedestal.
Finding an Item Room
An Item Room can be found on almost every single Floor. The only Floors they do not appear on are The Dark Room and The Chest. There is only one Item Room per floor, unless it is an XL Floor, in which there will be two Item Rooms. Besides the first Floor, every Item Room bust be unlocked with a key. It can, however, be blasted into with a bomb if accessing it from a Secret or Super Secret Room.