SRD:Anarchic

Anarchic: An anarchic weapon is chaotically aligned and infused with the power of chaos. It makes the weapon chaos-aligned and thus bypasses the corresponding damage reduction. It deals an extra 2d6 points of damage against all of lawful alignment. It bestows one negative level on any lawful creature attempting to wield it. The negative level remains as long as the weapon is in hand and disappears when the weapon is no longer wielded. This negative level never results in actual level loss, but it cannot be overcome in any way (including restoration spells) while the weapon is wielded. Bows, crossbows, and slings so crafted bestow the chaotic power upon their ammunition.

Moderate evocation [chaotic]; CL 7th; Craft Magical Arms and Armor, chaos hammer, ''creator must be chaotic; Price +2 bonus.