Well, as we played it, we treated that attribute roll as a skill roll (with all bonuses that apply). But we couldnt help wondering; should we just used the "clean attribue" or perhaps gone with the combat bonuses… a bit uncertain myself tbh

The active player (A) tests his chosen attribute vs 10. Since it's a skill test, a 1 will fail regardless of your attribute. If he passes, he chooses another player (B) to test the same attribute, but B's test will be against the SKILL SCORE that player A got in his skill test. So if A has maxed Strength and rolls a 5 with no other modifiers, B would test Strength vs 17 (12+5). Haven't played it yet, but I'm already seeing some nasty potential with the Canoness, whose skill tests explode on a 5 or 6, as well as the Psyker (yeah, shocker ) cycling those 6s to get very high skill scores in the 20s that will be very hard to pass for another character.