From Dungeons of Dredmor Wiki

You are repaying your debt with the strength of your flesh.

Debuff:

• -1
• -2
• -2
• -2

Duration: 13 turns

Curse of Weakness is a detrimental effect (Curse) that affects characters that cast spells such as Mark of Chthon and Tenebrous Rift.

It is a side-effect of spells cast by characters with the Necronomiconomics skill tree.