Honest (3.5e Flaw)
From D&D Wiki
Summary: You cannot lie. Whenever you are put into a situation that would make you choose between telling the truth or telling a lie you will always tell the truth. While you may have various levels of what is "truth" and what is a "lie" you always have to abide by your rule. If you believe that it is lying to omit something then you cannot omit that thing.
If put in a life or death situation you may roll a Will save (DC 20) to lie to save either your life or those that you care about. If it was a vow of honesty that you took then you feel guilty for 1d4 hours. If it is a natural compulsion to tell the truth then you are amazed in your ability to lie for a time before you find that you still cannot lie.
Benefit: Bonus Feat.