Psychic, yes. Psychic Power, no. Nowhere in the book does it say the ability either is a Psychic Power, or follows the rules for Psychic Powers. It just says to make a Focus Power Test, which is different from a Focus Power action.

So which power rating do you apply to it?

I would use my character's base Psy Rating.

 Why? The rating you use for the Focus Power Test isn't your psy rating, but the one you choose from the Fettered/Unfettered/Pushed rules. If there's no choosing between them, neither is there any specific psy rating since the Focus Power Test only says "you may add a bonus to your Focus Power Test equal to 5 times the Psy Rating used for the power". That you use your "base" psy rating is an interpretation on your part, but since you're so adamant about following the RAW...

 So you agree that RAW is broken and needs to be interpreted one way or the other to work.

 Um... was that ever the question? No RPG works by following the RAW, that's why tabletop gaming hasn't been completely replaced by video games. However, given the substantial evidence from the tabletop and more importantly the incarnations of Force Weapons in DH and RT, it's fairly clear what interpretation to choose - the one that doesn't suddenly require to construct a mechanic never seen in the rest of the game, a psychic action that doesn't conform to the Fettered/Unfettered/Push Focus Power rules and just picks out an arbitrary part of it.

Cifer said:

We agree on something sir. A psychic (force) weapon, being used by a psyker, making a test based on his psy-rating using same attribute as a psychic power, said test being described in the psychic (force) section. Jeez.

 Hmm... apparently it's impossible to damage an opponent with a spell using RAW as well. The rules for determining hit location are dependent specifically on having a WS or BS roll to reverse, which Smite doesn't have. Therefore, no way to determine where it hits for armor reduction or critical effect.

This game has more loopholes than Exalted...

 IIRC, whenever damage occurs to a nonspecific location, it should be assumed to be the body.

Cifer said:

I know that's the case for when a character is taking damage from being on fire, but I don't think that's a general rule listed anywhere.

I could be wrong, though.

evilamericorp said:

It's also the case for Blast weapons.  Without trudging through the rules looking for a specific line hidden away in a paragraph somewhere, it would likley be safe to consider that to be a standard determiner.

There are some Psychic Powers which state what location they effect; Soul Killer from Radical's Handbook applies any critical damage simultaneously to both the head and body on the Explosive table.  It also ignores armor unless warded.  In the case of a Force Weapon, presumably the extra damage is channeled into the location wear the weapon struck.

-=Brother Praetus=-

The easiest way to do it would be to class psychic powers that do damage as "attacks," and reverse the WP roll just like WS or BS. That was most likely the intention. I'm just saying that I doubt the line you are talking about exists, and that the psychic power section especially, and the book as a whole, feel like an unfinished product. The examples don't line up with the rules, some rules reference other rules that don't exist, and there are glaring grammatical errors on almost every page. The interpretation itself isn't the problem, it's the fact that I have to change the rules as written just to be able to play the game.

Agreed, the rules around Force weapons are obscure and cloudy at best, and require house rulings on a number of ambiguities. 

1) Force Weapons should read something along the lines of as a free action use a psychic power (i.e. not read Focus Power Test, it skips a bunch of stages) that give +1d10 per degree of success.

3) As written, you make a focus power test, but do not power level. A GM must decide whether they want to standardise it with the rest of the psychic powers, or use quasi-RaW and lock it at Unfettered. Obviously,the only benefit to Pushing (and downside to fettering) is the 5xPR bonus to the Focus Power test. However, I don't like the idea of pushing on opposed rolls. If I'm having PP/Potw, I don't want any additional chance of whiffing the power. To be honest, I don't see much point using Force Weapons above Fettered. Sword already perform as well as Power Swords at PR4, and going by all the pre-written material, Power Fields won't do bugger all to Tyranids (please note the limited scope of this statement). Fettered gives (a starting Librarian) ~55% chance of doing up +5d10 damage.  Unfettered only gives +5% (again, at starting). In terms of risk, I would only consider Unfettering on a Force Weapon at PR8. Pushing is contentious because of the discrepancy in point 4...

2) Opposed tests, as written, don't subtract DoS from the other roller. They are just used to determine who wins. In this case, if the Librarian scored 4 degrees of success and his opponenent scores 1, the Librarian does +4d10.

4) Pushing. Discrepancy between the example and the text. The rules text tells us it's +3. The Example tells us it's +3 because that's the willpower bonus of the Librarian in the example (I'd also like to point out that a PR4 Librarian with a Willpower bonus of 3 is likely under the very watchful eye of the Ordo Hereticus/Malleus...lame-ass). Again, a GM must pick. Going by the example, an advanced Librarian can push for a WP bonus of 6? That's double the texts +3. Furthermore, the Librarian in only receiving a +10 bonus and not +20 (5x4PR). Shoddy. 

Furthermore, discussion of Dark Heresy and Rogue Trader isn't really all that great. Deathwatch should be self-contained and work of the book. Using those games for context to get to the Rules as Intended is great, but if that is even necessary, it devalues Deathwatch as a standalone product.

Any activity that draws psychic energy from the warp should have the chance of phenomena/perils unless it explicitly says otherwise.  The fact that your making a focus power test implies that all the benefits and drawbacks of such a test are present unless it states the contrary.

Benefits = being able to choose the power level

Drawbacks = being able to trigger negative effects

At least that's the way our group interpreted the rules.

EDIT: And as far as hit location is considered, you already have the hit location for force weapons dictated by the actual attack of the weapon.

Cuagau said:

This is one of the biggest problems I had. It's like they went through several revisions to the Psychic Powers rules, but didn't take out all the references to rules that didn't make it into the final product.

The Focus Power Action states that all Psychic Powers should have at least one action subtype (attack, movement, melee, defense, etc.), but not a single one does. This would lead me to believe that damaging powers were meant to be included in the rules as "attacks" and therefore use the same rules as ranged and melee for hitting body locations (which they currently have no rules for), and also for things like righteous fury.

Bunad said:

That wasn't the issue. How do you determine hit location for Smite, or any other regular Psychic Power? The only rules for determining hit location in the book say that you need to have a WS or BS roll to reverse the digits of.