Oaths with system???

[drexes]

I have an idea that centers around a Blood Oath. A Blood Oath is the sacred oath of vengeance among one of the races of my world (The fianna--celtic elves). It is there most sacred oath and other fianna will not interfere with a fianna who is thus Bloodsworn. The bloodsworn mark themselves by placing a bloody handprint upon thier own face. Once the act of vengeance is carried out a bloodsworn fiannan must recieve an atonement spell in order to become 'unsworn'. The fianna take the oath very seriously and any interference is considered akin to blasphemy or heresy. What I don't know is what effect the Oath has while the Fianna is under it...

I was wondering if anyone had a system for Oath type effects. I think the effects should be both bad and good. Does anybody else have any thoughts? Any help would be appreciated.

Drexes

 

[Bihor]

I think Malhavoc as something like that in The Book of Hallowed Might

 

[DarkKestral]

I would say that it should be something like:

Fiannan Blood Oath (su): While underneath the effects of a Blood Oath, a player...

Gains a +4 bonus to will saves involving mind-affecting effects involving the Oath, but a -4 penalty to all other will saves.

Gains the effects of the feat Diehard in the presence (100 ft) of the target of the oath. However, afterwards, the player must make a DC 15 fort save or else they will die from exertion, though if they survive, they remain under the effects of the feat for an addition 5 rounds. (if the player already has Diehard or an equivalent, the better version applies)

Gains a -2 penalty to all skill checks not associated with the oath, and a +2 bonus to those made as part of satisfying the oath.

This works?