Arkham Horror Cursed Dice Set: - Rules of Play says:
Prepare yourself for a new weapon in the ongoing fight to keep the streets of Arkham safe!
The Arkham Horror "Cursed" Dice Set contains five high-quality, crafted, polyhedral red dice for use in Arkham Horror. They are cast from hand-carved original sculpts, and feature ornately detailed faces as well as Elder signs on the "6" side to indicate a success.