The much-maligned mysterious force is a random level teleportation effect that occurs one quarter of the time when trying to climb stairs or using a cursed potion of gain level in Gehennom with the Amulet of Yendor. Lawful characters are dumped up to three levels below their current location; for neutral players it is up to two and for chaotic it is up to one. (This includes occasionally being teleported around the level, a kind of "zero level drop".) Covetous monsters (such as the Wizard of Yendor) may also be affected by the force when they try to flee upstairs with the amulet. Unlike the player, monsters will always be sent exactly one level down by the force. These effects are summarized in the table below.