The Magic Hoard - Shieldbreaker

There doesn't seem to be a lot of magical pole arms, so here's a rather powerful one...

Shieldbreaker: This +4 halberd destroys any shield it hits. If a creature bearing a shield is damaged by Shieldbreaker during a combat round, its shield must succeed on a crushing blow or be rendered useless. Wooden shields are splintered, but metal shields can be repair by a skilled smith. A character with a shield may choose to deliberately not use it when fighting Shieldbreaker, but the character loses the benefit of the shield to his AC and also suffers an additional -1 penalty to AC because of the unnatural behavior. However, this completely protects the shield from Shieldbreaker. Experience Point Value: 3,000 G. P. Value: 15,000.