Ok, I'm having quite a bit of problem, but our group just started.

How does a Pysker cast a spell in Dark Heresy?

Everyone seems to rely on Weapon skill or Ballistic skill, adding bonus from Ag/Str, but the Spellcasting seems to be using some other rules.

The only ruling I see is :
(PsyRating)xD6+Will power bonus vs. the Spell Threshold.

Psyker power like "Psychic Stench" (Threshold 6) is always casted successfully with a Psyker (Psyrating1 + 50 in will)?

Is there any other test to take?
What would be the steps to take, let's say, if a Psyker attempt to cast, from the very start?

• Declare you're using a Focus Power Action to try to manifest the Psychic Power. How much time (Half-, Full-, Extended-Action) it takes to perform the Focus Power Action is listed in the entry of each individual Psychic Power.
• Make a Power Roll . This a number of d10 dice equal to your Psy Rating, with your Willpower Bonus as a modifier.
• Compare what you rolled to the Psychic Power's Threshold , which you'll find in the entry for the Psychic Power you're trying to manifest.
• If your Power Roll equals or beats the Psychic Power's Threshold, you have manifested the Psychic Power
• If your Power Roll is less than the Psychic Power's Threshold, you have failed to manifest the Psychic Power
• If you roll any 9's on your Power Roll dice (that's the result on the individual dice, not the total of the roll), you must roll on the Psychic Phenomena table on p.162 . Psychic Phenomena can happen whether or not you succeed manifesting the Psychic Power you're trying to use.

Stinky The Psyker has a Psy Rating of 1 and a Willpower Bonus of 3, and he wants to invoke the Psychic Stench power.

First he checks that invoking Psychic Stench is a Half Action Focus Power Miscellaneous Action (yes, DH's keywords are a mess).

Since his Psy Rating is 1, he gets to roll a single d10, and adds his Willpower Bonus to the result.

Stinky The Psyker rolls 9 and adds 3 for his Willpower Bonus, for a total of 12.

He compares his Power Roll result of 12 to the Threshold of Psychic Stench, which is 5, and sees he has more than succeeded.

Unfortunately he also managed to roll a 9 on the die, so Stinky has to roll on the Psychic Phenomena table, and if he's unlucky enough (and all Psykers are), he'll end up rolling on the Perils of The Warp table.

Note three final things:

• Certain powers have something caled Overbleed, which basically makes them better if you beat their Threshold by enough.
• You can roll as few d10 for your Power Roll as you wish, and moderation is life for Dark Heresy Psykers.
• Don't ever use a power if you don't have Fate Points to Burn. If you do, there's a small but very real chance you'll end up killing the entire party.

Thanks a lot!

I'll sure try my best to survive a couple of games

Don't ever use a power if you don't have Fate Points to Burn. If you do, there's a small but very real chance you'll end up killing the entire party.

This is really just personal preference but as a DM I encourage my psyker players to roll maximum dice all the time, fate points or not be danged.

We don't use DH RAW any more, but IMO they're a bad fit for long term campaign play. At least unless you houserule something like any player being able to Fate Burn nuclear psykers away.

Can a Psyker be from a Noble Family? Or it's such a shame to be a psyker that you get kick out of the family?

Don't ever use a power if you don't have Fate Points to Burn. If you do, there's a small but very real chance you'll end up killing the entire party.

This is really just personal preference but as a DM I encourage my psyker players to roll maximum dice all the time, fate points or not be danged.

Nadia1992, on 08 Nov 2013 - 12:46 AM, said:

Can a Psyker be from a Noble Family? Or it's such a shame to be a psyker that you get kick out of the family?

Both?

Imperial Psykers can have the Hive World Homeworld, and per p.32 in "The Past" section of the Core rules, Hive Worlders can be nobles.

Alternatively a PC with the Noble Homeworld from the Inquisitor's Handbook could be an unsanctioned Psyker, but you probably shouldn't allow that. Unsanctioned Psykers in DH are begging to be killed by the entire setting, the other PCs included. So.. It'd probably not be much fun for anyone.

An Imperial Psyker whose name has been stricken from the records of a noble house is very much in line with the fluff, and a nice setup for both personal drama and ideological conflict. A mother might still try to keep in contact with the Psyker, or vice versa, or a younger brother might have been so affected by the loss and injustice of it all, that he's now secretly running a cult that tries to rescue Psykers from the Black Ships, convinced that that the Psychic mutation is really the next step in human evolution.

As for Psykers being more powerful than other characters, it depends a lot on the kind of game you play. If the Psyker is free to use his powers, then yes, he'll eventually be the best at everything. But if there tends to be serious in-fiction repercussions for using psychic powers, then there'll be plenty of room for the other PCs to shine.

Personally I think the most problematic aspect of Imperial Psykers in DH is their Psyniscience Skill. It can very easily get in the way of your plans as a GM, if you don't keep it in mind while prepping stuff.

The most overpowered thing about Imperial Psykers is that they can make it incredibly hard to seriously threaten the PCs in combat encounters, without creating a significant risk of killing the entire party outright. But that goes for Tech-Priests too. Possibly even more so. Because Tech-Priests can become unbelievably killy, while simultaneously being the hardest PC to kill. As they rank up, they eventually become a bit like running a terminator alingside a bunch of far more ordinary & squishy human beings.

Can a Psyker be from a Noble Family? Or it's such a shame to be a psyker that you get kick out of the family?

Homeworlds are a bit of a mess when it comes to certain careers, but yes, by the rules, psykers can definitely be from noble families. However, it is unlikely that they still maintain any concrete ties with said families, seeing as how sanctioned psykers are likely to have spent several years, perhaps decades, either being trained and going through the sanctioning process, or in direct servitude to the Scholastia Psykana and the Imperium.