[Graeme Dice]

Originally posted by Borg:
So, one lvl 2 priest has a 40% chance
2 lvl 2 priests would have 80% chance to increase the Dominion from 1 to 2 (but even together they would not be able to raise the dominion above 2)

Each priest still has only a 40% chance to raise dominion. Two priests will give you two independent priest checks. This means that the overall chance to increase your dominion will be 1-((1-0.4)^2) or 64%.