Hi, I've been playing Dark Heresy with a few friends for about a month now and just recently started out again as a Psyker.

In the last session my GM used psychic creatures against us, and they were almost all using Distort Vision against us. Since I'm focusing psychic abilities on this Psyker, I primarily use Psychic Abilities. And this question arose in that session:

How do Psychic Powers work against an enemy that is distorted via Distort Vision? It says attacks are at -30, but Psychic Abilities don't work like that.

Any ideas would be great, thanks!

You can see in the "psyniscience" skill desription that a psyker has to achive 2 succeses to know the exact location of the target. Usually you need to see the target when you use powers against it or know where the target is. If the power works on some area and the target is in this area, power should work.

So first, team psyker has to get 2 DoS on psyniscience test to know where target who used "distort vision" is. He can show this location to his teammates and they have then -30 to attacks against this target. But psyker can't attack target cause psyniscience is a full action.

So if I have a Perception of 33, and pass a Psyniscience (+0) test by rolling 13 or lower, I can see distorted enemies even if they refresh distort vision?

No, I think you can see them only to the the beginning of their next turn. If they use "distort vision" again they can change their location, so you have to test psyniscience again. But it can depends on GM interpretation I think. Bacause lets say enemy used "distort vision" in his turn and moved. You used psyniscience in your turn and get 2 DoS so you know where he is, you can see his warp signature. Then in his next turn he uses it again and his image reapered somewhere but you still knows where he is thanks to psyniscience test before. So if Gm allows "psyniscience" to work longer you can see him if not you need to do psyniscience test again.

I honestly think it's kind of unfair how I have to pass a Psyniscience test to use any psychic power on a distorted person, yet anyone else can make a weapon or ballistic skill test on them at -30 and potentially hit them.

The key is this sentence : "All attacks against you, should your position be discovered by means of psyniscience test, are very hard (-30)"

If I understand it corectly, your teamates can not attack distorted person at all, unless you make Psyniscience test with 2 DoS and point them the enemy location, then they get -30 to all attacks. But I'm not an englishman so maybe somebody else could help with this sentence.

I think the Psyniscience test is a free action, in this case. You are also forgetting the errata, which as a free release I can put here:

Distort Vision on page 166 should have its description changed to:

“With this power your physical form distorts and you almost
fade from view. Your precise location becomes extremely diffi cult
to discern, and until the start of your next turn all attacks against
you suffer a –30 penalty to hit. Characters with the Blind Fighting
Talent only suffer a –10 penalty. A successful Challenging (+0)
Psyniscience Test removes this penalty for the attacker. Sensory
equipment based on standard optical sensors are fooled by this
power; ones that read thermal patterns, use motion sensors, or rely
on some other form of detection are not. Creatures and sensors
that do not rely on sight are not affected by this power.”

As you can see, you can use your Psychic abilities on him. This would not effect something like Spasm, which requires no attack roll. Presyense/IR Goggles or gun sights take no penalty. I would house rule that attack powers, such as Bio-lightning which require no attack roll are instead made 3 points of Threshold more difficult to reflect the trouble discerning his presence. Obviously that's not a realistic effect, as Threshold reflects the difficulty manifesting rather then hitting, but it seems balanced mechanically. Things like Force Bolt would simply suffer the penalty to the WP bonus, though I would halve it since WP tests to hit are never subject to bonuses the way ranged attacks are.

This is all just opinion on my part, and is subject to your GM's fiat, as is everything, but hopefully this let's you make a reasonable argument.

"Psykers are the future!" -BBT, a Polypsykana Advocate

Deluril said:

What scares me most about this idea is the sheer number of phenomena rolls those beasts will trigger. Note that the errata includes the line: A Psyker is required to roll at least one die to manifest an ability. Which means that each beast has a 10% chance to trigger a phenomena each turn (unless they also get the fettered/unfettered/push rule from Ascension).

My advise for that situation: Nuke the place from orbit before they do something worse to it.

There were several Psychic phenomena occuring in that area as I was also using quite a few psychic abilities. A lot of us became a tiny bit corrupt from it (woo, Peril of the Warp!), which kinda furthers what I want to do with my character in this game anywho. Also, we're in sewer tunnels, so I doubt we could safely nuke the place.

On the topic of Distort Vision vs. Psychic Powers, what about Sense Presence? The Errata states that it shows the direction and size of any living creatures within range. Using this along with my Photo-visors and normal vision (i have nightsiders as well, which kinda negates the usefulness of the photo-visors), would this not be suitable to properly determine the location of the distorted enemies and thus use my abilities on them normally? It sounds like a fair counter to me. Beats using Psyniscience tests all the time, in my opinion.

Also, I believe Psyniscience tests are Full Actions (page 105, at the end of 'Psyniscience').

Trying to find something and detecting the source of a psychic power targeting you (sort of) are very different things, imo, and I would view this power as an exception to the Psyniscience rule. A Psyker (or other with the skill) should be able to make a free test to discover the location. Sense presence would negate the penalty entirely, since it determines the location and is not visually based.