Rosary Bead

Effects

Increases the chance to have an (Angel Room) Angel Room replace a (Devil Room) Devil Room, from 50% (base chance) to 75%.
Increases the chance to find (The Bible) The Bible to 45% in the (Library) Library and in the (Shop) Shop to 13%.

The increased chance will not provide an Angel Room on Basement II. And as of Repentance, due to an Angel Room being guaranteed after skipping the first Devil Deal, Rosary Bead only increases in usefulness after the first Angel Room has been encountered.
If a Devil Deal or (Removed in Repentance) (Black Market) Black Market deal has been paid, an Angel Room will not spawn, even with Rosary Bead.
This item does not increase the chance for an Angel/Devil Room Door to spawn when a Boss is killed, unlike (Goat Head) Goat Head or (The Book of Belial) The Book of Belial.