Okay, so I'm not quite sure on this one, fluff based and all. Do Blanks just always have their Blankness in its maximum capacity at all times? When they are young, is the potential maximum? How do they work? What affects blankness?

In reverse order, first with the subject changed to psykers, then the same questions will be answered vis-a-vis blanks.

What affects Psychic power? Plot, and possibly warp exposure, genetic makeup, or the grace of the Emperor. After that, training.

How do they work? Plot-powered, but they generate an area of warp-powered effects.

When they are young, what is the potential maximum? [bold is my edit, assumed question] Whatever plot requires, but for a PC psyker, generally not too powerful.

Do Psykers just always have their Psychic power at its maximum capacity at all times? No, see fettered, unfettered and pushing.

Now, Blanks.

What affects Blankness? Plot, and possibly warp exposure, genetic makeup, or the grace of the Emperor. After that, training seems to matter.

How do they work? Plot-powered, but they generate an area of "no warp shenanigans here, also please hate me."

When they are young, what is the potential maximum? [bold is my edit, assumed question] Whatever plot requires, but for a PC blank, generally not too powerful.

Do Blanks just always have their Blankness in its maximum capacity at all times? This is trickier, and largely why I posted the responses as relevant to psykers first. Blanks are functionally antipsykers, so it seems reasonable that they could restrict their aura, relax it to an unfettered state, or push to expand or enforce the aura. However, the answer is still "whatever plot, and your game, requires."

In fluff terms from many of the novels, the strength of psykers and anti-psykers seem to be graded on something called "The Assignment".

It all uses letters of the Greek alphabet with your average garden variety Psyker likely being an Iota, Epsilon or Delta level power. There are ones below that and these are people with slightly higher brain activity or a basic fluke like power. The select few though are Gamma level (such as supposedly Gideon Ravenor). At this level we're talking some quite potent abilities. After that we get the Beta, Alpha and Alpha Plus. These sorts of psykers are ones who can rip titans apart with just a thought and decimate or dominate entire armies. The stronger the power, the more increasingly dangerous but also the more unstable the person is likely to become, being unable to control so much power.

Many people will start with the basic innate levels of psychic abilities but it will start to come to manifest early in life similar to mutations in the X-Men series and usually as a result of times of increased emotional activity where these abilities trigger. Something significant enough will usually happen which will warrant the attention of the Inquisitor. At which point many are taken away for the sanctioning. A psykers power I would gather is fairly absolute, it's like the force. You only have a fixed potential in it but the training is needed to show you how to tap into all of it and use its power properly lest you use it wrong and get ripped apart by a daemon.

The reverse end of the scale then, which is what you're after, uses the bottom end of the alphabet. Sigma or Tau level are those who are slightly resistant against it. You go down a stage to Upsilon which have mostly an immunity and then you get Omega level. These are your blanks. There are different levels of positive strength and therefore it serves to reason that there are different levels of negative strength. The core thing though is that any blank is totally immune to any and all psychic powers or techniques. They hurt a psyker to be around and themselves project a radius around them (plot/book dependent but usually a couple of meters) whereby you cannot manifest techniques or affect things inside that radius. This is of course not to say they cannot be harmed by consequences of power. So they might be immune to telekinesis but you can still use telekinesis to drop a boulder on them since blank doesn't affect gravity!

Blanks basically disrupt the warp. They create a field which affects their ability to focus and disrupts the psyker. Even daemons dislike it and their aura repels them (doing double warp instability in some books).

A blank is basically born a blank and I believe it was written somewhere that due to the aura of fear and loathing that an Omega generates on Joe Bloggs, not many of them reach maturity and end up killed because of their aura as angry mob tends to want to kill them first. Not actually due to their personality, heck many of them can be quite pleasant, the aura overrules it. It's why the Inquisition and/or Culexus temple are keen to pick them up before then. This ability as well is always on, it's not a toggle-able. From what I recall from the part way I got through the Eisenhorn series, his retinue Alizebeth Bequin used to work as a pleasure girl however never did overly well at it because despite her reported beauty in the books, that anti-psyker fear and loathing field didn't help her.

Annaamarth, I appreciate the help, its what I have been thinking and how the blanks work

Calgor Grim, Can a Blank Expand his field of effect if they concentrate on the ability, or say, suppress someone harder, etc?

Annaamarth, I appreciate the help, its what I have been thinking and how the blanks work

Calgor Grim, Can a Blank Expand his field of effect if they concentrate on the ability, or say, suppress someone harder, etc?

Looking into it further with more digging since this morning, Ravenor did have an untouchable with him in his retinue which had an on/off function. He had a fitted inhibitor which would restrict his anti-psi field. This suggests you may be able to alter this down at least but it is the only reference I have been able to find of this so do feel free to take this with scepticism. I would say though that the peak of blankness is their base abilities. They cannot perhaps become more blank or untouchable however a Psyker can get slightly more powerful as they can tap into deeper depths of the warp. Look at it like temperature, cold can only go down to around -273 degrees celsius (absolute zero). I see a blank as the same, there is only a certain level of anti-psyker. Warm can go much higher though as Psykers give themselves (sometimes literally) to the forces of Chaos for more power.

There's nothing fully concrete or comparative either whether a max Alpha Plus level psyker at peak of derangement and infinite power can obliterate through the null aura of a Culexus assassin or whether it would simply fizzle. GW didn't touch on all that so it's open for debate.

A few odds'n'ends-

The Eisenhorn series features a Null character who sets up a school for Nulls; it's been years since I read it, but I seem to recall that they are trained to expand and contract their null-auras.

Dan Abnett also intorduced the concept of 'inhibitor devices' that allow a pariah's null filed to be 'turned off'- it's in the form of a colar in the Ravenor series, and a wrist-cuff in the recent novel Pariah .

The Dark Heresy supplement The Radical's Hardbook has crunch-rules for PC Nulls (which are much more popular than the terrible DH2Beta Null rules [which I desperately hope get dropped from DH2 ], which- believe it or not- actually allow Null Psykers as an option! WTF?!

The Black Library novel Atlas Infernal features an 'artifact' that is actually the preserved fetus of a mega-powered Null, which causes all Psykers in the vicinity (including Grey Knights) to simply keel over dead (?!). It's not a very good book...

The Dark Heresy supplement The Radical's Hardbook has crunch-rules for PC Nulls (which are much more popular than the terrible DH2Beta Null rules [which I desperately hope get dropped from DH2 ], which- believe it or not- actually allow Null Psykers as an option! WTF?!

Deranged idea...what's next, Khornate aligned psykers? Oh wait...Relic got there first

Caution, spoilers of DoW2 if you somehow haven't played it in however long it's been out!

It's weird, I always assumed my buddy made the limiter up. We did a d20 homebrew of DW in 2004, and the inquisitor we four were serving "loaned" us Draco. Draco was, for description sake, something akin to an Arbitrator or Judge, maybe an Acolyte, if Nulls can become Inquisitors, and he made the whole party uneasy. Our elder Inq Lord was a psyker, as was my Grey Knight, so Draco had a little box that he wore, and could turn on when he had to be near his master, or me/us. Didn't know that was real in the books, though I did steal it for some of my own work. Likely less true, we also had it where if Draco was mostly dead, his null field fell. We were attacked by Cultists, and someone sniped him in the head with a big gun. Much of Draco's head was pulp, but we rolled and role-played to save him, and then the Sergeant/medic rolled amazing, and we actually got him back to home. Our Inquisitor was PISSED, since Draco isn't exactly replaceable, but he lived, and so we were excused. The next time we saw Draco, he had enough metal in the back of his head an Ork might've cheered for him

I like the RT rules in Navis Primer for Nulls. If they weren't so special snowflake, I'd hope to someday play one; I like the opportunity to get to play characters with such built-in inter-party chemistry, as well as always liking to play snowflake characters; it's a weakness, but only when my GM lets me get away with it.