Add the following to the list of Vows in Rule “2.5 Vows”:

Vow of Pacifism:  Monks undergoing this Vow shall not Pick a Fight.

In the Rule called “Fighting”, change the first occurence of

E then rolls DICEG, where G is eir opponant’s Temporary Fitness.

to

If eir opponent is not undergoing a Vow of Pacifism, E then rolls DICEG, where G is eir opponent’s Temporary Fitness.

Finally, in the Rule called “Fighting”, change

Being involved in a fight causes a loss of Integrity equal to 3*S for whoever starts it and 1*S for the other Monk. This may make eir Integrity negative.

to

Being involved in a fight causes a loss of Integrity equal to 3*S for whoever starts it and 1*S for the other Monk. If either Monk is undergoing a Vow of Pacifism, the Integrity loss for a Monk who starts a fight is 5*S (instead of 3*S). This loss may make either Monk’s Integrity negative.

To make things clear— The disadvantages of undergoing this Vow are:  an increased penalty for starting a fight (an extra 2*S, and the 5 for breaking the Vow) and, more importantly, the inability to defend oneself if picked on.
The only advantage (besides the usual advantage for undergoing a Vow) is the increased penalty to someone picking on you