So, this has happened at least 10 times in recent games that I was in. A team-mate would get hit, and either parry one and have another still hitting him, or try and parry but fail. Then, someone in my team would parry for him, blocking both hits. This made it almost impossible for the enemy to hit us, especially since when they would occasionally get a powerful hit, (that would cause a lot of damage, not nescesarily killing, but definitely causing critical damage. So, the question is: Can you spend your reaction to block an attack that wasn't directed at you?

Waaaghpower said:

I don't believe so. I don't have the Rulebook handy, but I'm pretty sure it says that reactions can be used only on things that effect the "reactor".

The bracked "Combat abstractions" on p191 implies that dodge and parry are YOUR last line of defense, not someone elses. But the Crusaders (Ascension class) special Ability nails it for me. With this he is allowed to püarry attacks against his Inquisitor. Why would he need this if he could do so regularly?

That said, I might allow it - assuming the parrying individual is within 10' of the target - at a negative (-20 say) and the additional assumption that he has used his parries for the round. (so should something now strike at him, he's out of luck)

As Schwarzie said the Crusader form Ascension is able to parry for a companion due to a special talent. Though everyone is able to make a Dodge test (-10 IIRC) to throw himself into a shot (and maybe also a melee attack (not sure)) targeting someone else as described in the Inquisitors Handbook.

There is no rule to allow you to parry for someone else, until ascension as mentioned.

You can however use your dodge take an attack for an ally (Dodge - Protect Ally, Inq Handbook pg 230)