Ruin

Regular 
Accelerates the natural process of decay on unliving materials. It rusts iron and steel, but has little effect on other metals unless maintained for a very long time. It causes organic material – leather, fur, wood, plastics, etc. – to decay to uselessness. Ceramics are unaffected by Ruin.

Duration: 1 minute. Each 1-minute casting has the general effect of aging the subject 5 years. It will remove 1 DR and 1 HP from most subjects. Weapons simply lose one grade of quality per casting, except for Very Fine weapons, which are unaffected! 
Cost: 2 per pound of material ruined. Same cost to maintain. 
Time to cast: 5 seconds per pound of material ruined. 
Prerequisites: Magery 1, Weaken, and Decay.