Azraiel said:

The main benefit of using Psy Rating in place of Willpower Bonus on psykers is scaling, rather than anything else - it actually makes the Fettered/Unfettered/Push rules work, by ensuring that a power used at the Fettered level is weaker than one used Unfettered (because you're using a lower Psy Rating), and that a Pushed power has a benefit to accompany the increased risk (because you're using a higher Psy Rating).

It's partly intended as a nerf to curb the excesses of certain powers that scale too far, but it's also intended to allow the Fettered/Unfettered/Push rules work as designed.

N0-1_H3r3 said:

Could you go into a little more detail as to what kind of changes you're advocating there, please? I was talking about the common suggestion of enforcing a substitution of Psy Rating in the place of the Psykers' Willpower Bonus for all formulas relating to powers, and how this actually leads to higher power levels, rather than a hearty kick in the shorts. Advocates of that idea usually forget that Unnatural Willpower also applies its modifier to Psy Rating for such calculations.

As an example; suppose an extremely veteran Primaris with 75 Willpower attains Rank 14, picking up Psy Rating 9 and Unnatural Willpower x2, doubling his Willpower bonus to 14. For the sake of keeping the example simple, I'll use the telekinetic power Force Bolt for these comparisons and discount talents such as Power Well and Discipline Mastery.

Under the normal rules, his Willpower bonus of 14 ups his base damage to D10+14, and he can roll one (1) to twelve (12) D10 to manifest powers, adding 14.

Under the commonly proposed alteration, he uses his Psy rating modifier of 18 instead, for D10+18 and 1D10 to 12D10 +18.

That's what I was talking about. It's not a very big buff, and I like that it puts Psykers on a more equal footing compared to each other without completely invalidating their Willpower advances, but whenever someone tries to push that idea I get the impression that they think it would be a really harsh nerf, not a buff/equaliser.

Azraiel said:

You've made a mistake here. In the Rogue Trader and Deathwatch version of the Psychic Power rules, Unnatural Willpower adds its modifier to Psy Rating after choosing Power Level (Fettered, Unfettered or Push) - so a psyker with Psy Rating 6 and Unnatural Willpower (x2) (like the Farseer in Lure of the Expanse) using his powers Unfettered has an effective Psy Rating of 8. In Black Crusade and Only War, Unnatural Willpower grants no bonus to Psy Rating whatsoever (though it provides a benefit to any Opposed Willpower Tests, which are the most common form of Focus Power Tests). I've never seen anything that would suggest that Unnatural Willpower multiplies Psy Rating.

The more important factor in making powers scale by PR is that they always scale by the psyker's effective PR at that particular moment - that is, a psyker using PR3 uses it not only for manifesting the power, but also for determining the power's effects. It firmly defines risk vs reward - the psyker has to risk more in order to make his powers more effective, but can minimise risk by reducing the potency of the power. Without that, there's no reason for a Psyker to use as few dice as possible, because the power remains equally effective however much Psy Rating he uses.

Azraiel said:

Using the clarification I've given above (removing Unnatural Willpower from the equation), a Rank 14 Primaris as you've stated can use his powers Fettered (Psy Rating 5 - 5d10+14, for 1d10+5 base damage, no risk of Psychic Phenomena), Unfettered (Psy Rating 9 - 9d10+14, 1d10+9 base damage, normal risk of Psychic Phenomena) or Pushed (Psy Rating 12 - 12d10+14, 1d10+12 base damage, guaranteed Psychic Phenomena).

Azraiel said:

I don't hold that it's a "really harsh nerf"; indeed, I know exactly what it'll do - I designed the version of the psychic power rules in Black Crusade (which were re-used subsequently for Only War), so I'm very familiar with how the system works.

Hah, you think you've got the rules straight in your head and then someone takes your logical analysis and makes you look stoopid. I hunted down my copy of Deathwatch and found the sidebar, right where I remember it on the page I remember finding it, and reading something very different to what I remember reading the first couple of times.

You appear to be entirely correct, friend. So while I have your attention, do you have any thoughts on Dark Heresy powers interacting with overbleed, specific powers that might fall short under your proposed alteration and the like? The people I game with are pretty big on the, I guess spirit or essence would be the right word, of the setting and lore. Without spending hours going over every power I can find to make an informed appraisal, I'd be concerned that some powers suffer a great deal that perhaps should not.

Apologies for the vaguness for the question, I'll try to be more specific. Telekinesis scales in very closeley spaced increments of overbleed and relies heavily on a key stat number, as I recall. I think I'd be concenred if a Psychokinetic/Telekinetic Primaris, the most potent subgroup of Psykers in the Imperium, couldn't at least lift one side of a Rhino APC in an emergency once they reach a good level of mental power, and flip, lift or hurl it violently at the very height of their power, while pushing, of course.

Azraiel said:

Right, so according to Forge World's Imperial Armour books, an unladen Rhino APC weighs 30 tonnes (30,000 kilograms). By my estimation, no psyker under the rules-as-written can lift that much mass anyway, let alone throw it. Lifting one side of it is a much less strenuous matter, but let's put that aside for a moment and look at the numbers.

Our sample character is a Rank 16 Primaris Psyker with Psy Rating 10, Power Well x2, Discipline Focus (Telekinesis), Unnatural Willpower (x3) and a Willpower of 75. The sample power is the Rank 1 Psychokinesis power, Lift, as it covers all the bases.

Going pure RAW, and Pushing: the character's average focus power roll is (from 13d10+25) 97. Against a Threshold of 14, that gives 83 points that can go towards overbleed, which varies by the way the power is used.

• The Move use allows the lifting of WPBx50kg, +50 per 5 overbleed, resulting in 2,850kg lifted.
• The Hurl use allows the psyker to throw an object weighing WPBx10kg, dealing 2d10+(1 per 5kg), resulting in a 210kg projectile dealing 2d10+42 damage. Overbleed adds no extra weight, but adds +1 damage per 2 points of overbleed and/or +1 projectile per 10 points of overbleed, in any combination.
• The Levitate use gives the Psyker the Flyer (WPB) trait, +1 per 4 points of overbleed. This gives us Flyer (41), which allows the character to move incredibly fast (a Run move at that speed gives 246m per round, which is just over 177 km/h, or 110 mph).

Replacing WPB with Psy Rating, and Pushing: the character's average focus power roll is still 97. Once again, against a Threshold of 14, that gives 83 points that can go towards overbleed, which varies by the way the power is used.

• The Move use allows the lifting of PRx50kg, +50 per 5 overbleed, resulting in 2,450kg lifted.
• The Hurl use allows the psyker to throw an object weighing PRx10kg, dealing 2d10+(1 per 5kg), resulting in a 130kg projectile dealing 2d10+26 damage. Overbleed adds no extra weight, but adds +1 damage per 2 points of overbleed and/or +1 projectile per 10 points of overbleed, in any combination.
• The Levitate use gives the Psyker the Flyer (PR) trait, +1 per 4 points of overbleed. This gives us Flyer (33), which still allows the character to move incredibly fast (a Run move at that speed gives 198m per round, which is just under 143 km/h, or 88 mph).

I think that it shows the differences - switching to PR takes the upper edge off of high-end psykers, but they're still able of lifting a couple of tonnes (roughly equivalent to what an armoured Astartes can lift, as it happens) if they go all-out. Of course, the latter version is also much less powerful if he goes Fettered (PR5, 5d10+25 gives a mean focus power roll of 53, which would Move 600kg, Hurl 3 50kg projectiles for 2d10+14 each, or Levitate with Flyer (8)… not unimpressive, it should be noted, particularly as that's without risk of Psychic Phenomena)

Cymbel said:

Oh, please. You'll never be able to take dat ass out of Assassins.

Boss Gitsmasha said:

That is what these guys are trying to do!

That's a nice and crunchy assessment, I very much appreciate the effort. I think we were a bit more lenient in our assessment of a Rhino’s weight in the absence of a tome such as Imperial Armour (Though I may be further prejudiced by Firaeveus Carron’s semi-famous and scornful appraisal of Rhinos as lowly “Metal Boxes!”), I'd like to see a bit more lifting power, if only because lifting huge weights with your mind is pretty freakin' metal. Still, that’s a respectable amount of mental force, that is! Certainly more than enough to meet any kind of practical need.

Also, the thought occurs that applying the conversion to Kineblades would weaken them quite a bit, though they would still be powerful enough to pretty reliably kill mooks, at the very least, which is a good and reasonable use for them anyway I think. I've yet to see a Psyker use them (My own Psyker relies pretty heavily on his swordsmanship and telekinetic/biomantic defences to bring foes down), but if any other posters have used them or seen them used I'd like to hear their stories, they do look like a fun weapon to have handy, on paper anyway.

Kasatka said:

Just a note as written the Temple assassin trait also allows the Assassin to dodge the un-dodgeable, admittedly a GM controlled circumstance, but as one of the examples use include invisible psychic attacks and a titans foot, there isn’t much they can’t dodge, however perfectly reasonable to have penalties to things that are normally undodgable.

If its that much of an issue then burst weapons are you friend, as at that point its not about passing its about passing by enough, after all even if you have a dodge of 110 if someone hits you with 5 bullets in a burst you’re dodge is down to 70 if you want to dodge of all of it, and even in the hands of a competent person (BS 40) a twin linked full burst at short range from an autogun will be an 90 to hit for a possible 10 hits, all of a sudden that dodge of 110 doesn’t look that good.

Or if you are an absolute git use an auto fire weapon on the person next to them and then every shot after the first hits the assassin