Corrupt

This spell enables a priest to contaminate pure water or substances, create a weak spot or irregularity (handhold or visible mark) in a wall of solid stone or surface of armor plate, and otherwise modify substances harmfully. Magical potions affected by a corrupt spell are reduced in the healing they bestow by 1d4 points; if no hit points are involved in their effect, their durations are reduced by 1d4 rounds. Holy water becomes merely water, but unholy water is doubled in efficacy (harmful effects). Normal drinking water remains drinkable, but it tastes tainted and does not cleanse things washed with it. Corrupted items have all their item saving throws against harm reduced by 3 points, unless they are magical. In addition, if an item is used as a weapon, the damage it inflicts is reduced by 2 points per attack for 1d3 turns. All magical functions and properties of enchanted items cease for 1d3 turns, though their own item saving throws are unaffected.

The caster of this spell must choose a single nonliving item or body of liquid to be affected by the spell. The magic does not affect all of a solid item larger in volume than the caster's body. In such cases, only a localized area is affected. For instance, a priest trying to contaminate a lake or large pool would succeed only in harming the water closest to his touch or the chosen area of effect that equals his body volume, not all the water). Corrupt involves a momentary flickering green radiance over the spot or item it is aimed at, but operates silently.

If three corrupt spells are cast on a single nonmagical item or on a specific spot in a large item (for instance, a place on a wall), the item must succeed at an item saving throw vs. acid or shatter/collapse/fall away, causing a hole at that location. Minor breakage in large items (in other words, a hole or cavity reaching a few inches into a thick stone wall) can be expanded by casting additional trios of corrupt spells. Through the use of corrupt, an imprisoned priest of Myrkul could, over time, breach a cell wall or cause manacles to fail.