All the rules are pretty clear, except on one detail:

Is the degrees of failure calculated on the difference of successes, regarding to the power used?

Example: A sorcerer heretic casts some bolt at a poor sod, which does 1d10 plus 2 per each opponents degree of failure.
sorcerer successes 3 times, while the target only once.

is the damage calculated this way:
targets degree of success - three sorcerers degree of success = two degrees of failure
(+1) - (+3) = -2
and would do 1d10+4 damage

or is it strictly checked from the enemys failures, which is in this case no failures, but does damage nevertheless, as the sorcerer succeeded more?
and would do 1d10 damage.

most bolt style powers do not use opposed psychic tests to determin there effect, they are treated like weapons, if someone uses doombolt the opponent uses dodge tests to avoid it not willpower tests to resist it.

the opposed psychic powers tests tend to be for things that you couldent dodge or parry but which mess with the target like shapechangeing or mind control.

see the gift of chaos power.

with gift of chaos damage is determined by total degrees of success based on an opposed test so yes you do damage for the degrees of success and degrees of opponents failure, its the same with the psychic test for useing a force weapon.

though in all cases I have ruled that regardless of how badly and opponent fails the sorcerer needs to succeed or the power fails.

I think it is official that psyker need to suceed because he wouldn't even manifest power otherwise. I'm quite sure that is written in the book somewhere (although it can be in rogue trader, I don't remember). Other than this you are right, it's total degrees of success.

Librarian said:

you don't even need to rule that, it's said in psychic power rules.

Librarian said:

So in the case of both succeeding, but the target less, I give the difference as degrees of failure?

PnPgamer said: