Hello!

I'm a little bit confused about usage of Interrogation skill.

Assume we have an Interrogator with WP 40 (moderate WP actually for a skilled interrogator) and special kit that provides him +10 to Interrogation. He is expert in Interrogation skill (not master)

So he has skill = 40 + 10 + 10 = 60

And we have an heretic with WP 65 (very good willpower) and special training talent that gives him +10 vs. Interrogation. He was trained to resist torments, for example.

So. In order to 'break' this heretic we need to make opposed roll 60 vs. 75. Each test requires 1d5 hours (~2.5 hours). Rules say that we have to fail by 5 degrees in order to give subject additional +30 to resist (so, it's impossible for us, with 60 skill we can't roll 110+ on 1d100)

Assume our interrogator decides to make 4 attempts. It will take only 4*2,5 = 10 hours in average and will inflict 4 fatigue to subject. If I'm correct, heretic will fail at least 1 opposed test...

What I'm trying to say. It is BORING. Using base rules even the toughest opponent will be 'broken' after 3-4 opposed tests!!! And what about stories in fluff that 'they interrogated him for several days... bla-bla-bla"??? Why interrogate for DAYS, if you can break even the mightiest of subjects in 2-3 opposed rolls that take only 1d5 hours???

I DON'T UNDERSTAND THIS.

Role-playing aside which can be incredibly fun, don't forget about using an excruciator. Add in some truth serum drugs like explication serum and maybe some mental probing/weakening by your resident psyker. Its all about variety with interrogations, just have fun with it.

BTW, any heretic with a willpower of 65 is probably a psyker and should be shot in the head fast. Remember, giving any heretic time to "think" about his interrogation is fine unless its a psyker. You don't want a psyker "think'n".

Minor quibble, the expected (mean) value for 1d5 is 3 not ~2.5.

Also bear in mind that your average heretic (TB 3) will probably fall unconscious with four levels of fatigue stopping the interrogation unless prevented.

IIRC just failing the test doesn't actually mean much in this situation. Degrees of sucess will matter, a simple pass may give you information but not the stuff you actually want or need. Breaking someone down in ~12 hours may be possible but it could still take them a month to divulge every last scrap of information, contact, protocol and cipher they have in their possession.