The Minor Power Resist Posession is cast as a Reaction, and reads:

"You create mental wards to shield your mind from the malign denizens of the warp. Any time in the next hour you may re-roll any failed Test to resist being possessed by a Daemon."

Question: Can you use this power to save your sorry skin if you during your own turn invoked the Perils of the Warp and rolls Deamonhost?

"Daemonhost: The Psyker must immediately pass a Very Hard (–30) Willpower Test or be possessed by a Daemon and become a Daemonhost!"

The wording would suggest that you can, but the mechanics of using a Reaction during your own turn, to React to something that is not really an attack, but the unfortunate consequences of your own Actions are somewhat unclear

I have always viewed the intent of the power to be used just for that purpose. So I would say yes, you can use it on your turn.

This power is active for an 1 hour. It shields you from beeing possesed. The reaction in the description is for the purpose of mechanic. The errata says: "A Psyker may manifest only one ability per Round with the exception of the Resist Possession power". So I think you can use it as a reaction in your turn even if you used another ability, even if reaction is only usable not in your turn.

Sounds pretty much exactly like what the power is supposed to be for.

Yes, I suppose so.

But what if he then manifests another Perils of the Warp while trying to manifest this power as a reaction, and gets another posession result?

@ Darth Smeg:

I have an IN GAME solution to perils of the warp.

The rest of the party should blow the Psyker away, NOW!. Having been the victim of our Psyker rolling a demonhost result last session (burnt fate points) my Feral World Assassin now firmly believes that all Witches are valid targets. (He's been shagged by psykers three sessions in a row, our Adept manifested powers and got taken by the black ships, and now the party psyker turns into a blo*dy demon while performing healing?! It's too much)

"Jungo used to fink muties was baddest, now Jungo knows witches is worse. Kill 'em all, burn the heretics". Jungo Max: Feral World Assassin.

Needless to say, the Psyker is no longer with the party (..blows smoke from the muzzle of his Orthlack Mk IV).

Not a solution to your problem I know, but worth sharing.

Darth Smeg said:

It doesn't matter. Protection works for 1 hour after casting, so you can reroll any failed roll on possesion.

"Any time in the next hour you may re-roll any failed Test to resist being possessed by a Daemon."

The reason I asked was because the power is cast as a Reaction, signifying you can cast it after a nasty deamon has "attacked" you with a posession attemts. Same way you can dodge an incoming attack.

But in the case of the Perils of the Warp, there is no sorceror or demon "attacking" you, it's you! You, yourself, by messing with the warp and losing control. So now you have to "React" to yourself, by manifesting another power.

And that, I believe, is not possible? Was there not some text saying you could not make another Manifest Power action in the same round?

And as for my silly little suggestion, it would be amusing if he got posessed by 2 deamons at the same time. Or would the first deamon be posessed by the second one? (not supposed to be a serious question)

Nevermind, I see this has been adressed in the Errata (p9):

"A Psyker may manifest only one ability per Round with the exception of the Resist Possession power . A Psyker is required to roll at least one die to manifest an ability.”

However, this does not mean you get to react to yourself. If you could not make this resistance attempt at other attacks if you had used some psy power, this power would be completely useless.

The way I see it, Resisting your own Perils-mishaps is like trying to Dodge your own Eviscerater if you mess up your attack and have it smack yourself in the head.

The way I see it, Resisting your own Perils-mishaps is like trying to Dodge your own Eviscerater if you mess up your attack and have it smack yourself in the head.

Apart from the fact that Dodge is a specific type of reaction that can be called only when you're being attack by something dodgeable, yes. Resist Possession has no such limits and considering the point of the power, why should it?

Well, because it means you'd be doing 2 things at once.

The deamonic possession caused by the Perils happens because you lose control as you attempt to manifest a power. Should you now be allowed to attempt to manifest a SECOND power, and get the benefits of this second power retroactively to aid you while losing control of the original manifestation?

Reactions are used when it is not your turn, letting you act "between turns" as it were, during someone elses turn. But now you get to React during your own turn, to your own mishap, and somehow still have time to complete a second manifestation before suffering the effects of the first.

I can see your point, but it still seems a bit.... off.

Replying to myself here, must be losing my mind

Core rulebook p188:

Reactions
A Reaction is an Action that is made in response to some event such as an attack. All characters receive one Reaction each Round, which may only be used when it is not their Turn . Examples include making a Dodge Test or Parrying an attack.

And from the Power description on p 167:

Resist PossessIon
Threshold : 6
Focus Time : Reaction

From page 161 it is clear that the psychic phenomena occour instantly:

"These psychic disturbances are rarely dangerous (most of the time). However, they do instantly alert others to the presence of the Psyker"

The Perils description on p 163 also:

"Daemonhost: The Psyker must immediately pass a Very Hard (–30) Willpower Test or be possessed by a Daemon"

So, to answer my own question: Using the power to resist the effects of a Perils of the Warp caused posession is not possible, as he would need to use a reaction to manifest the power, which is not possible to do on your own turn.

I see now that my question was imprecicely worded, and I agree without reservation that if a Psycher has successfully manifested the power before the Perils occur, he would gain the benefit. My question was (at least ment to be) if he could cast it once the Peril actually happens.

But you can use a reaction on your own turn. Furious Assault allows that so why not this? Someone mentioned above that this is the only psyker power you can use in a turn where you have already used a one so this is my take on things:

• If you use it as a preparation, you are covered and do not need to use a reaction - it's already in effect, OR
• You can use it as a reaction, but that is your reaction for the round (not so great if you're toe to toe with a badass).

HOWEVER if you use it as a reaction and then invoke perils of the warp you are proper screwed. In the first instance above where you use it as prep and then invoke perils some GMs may choose to not allow a reaction because it is not combat (I would though because that's the point of the power being a reaction).

PSYKER "I cast firebolt at the heretic, and roll ..clatter.. success, oh **** a nine, perils of the warp!"

GM "The heretic burns, roll for perils"

PSYKER ..clatter.. "Oh no, Demonhost, I activate resist possession as my reaction."

GM " Okay, make the activation roll."

PSYKER ..clatter.. " I succeed, oh **** another nine, perils of the warp!"

GM "You successfully resist posession but open youself to the warp in doing so, roll for perils buddy."

PLAYER .. clatter .." aw ****, you're not gonna believe this!"

( REST OF PARTY "All together now... becoming a Demonhost is HERE-ES-SEE!, ZAP ZAP ZAP!" )

<Pedantic rules lawyer>Actually, Furious Assault lets you "spend your Reaction to make an extra attack". So you're not actually Making a Reaction, you're sacrificing your ability to make one in order to make another Attack Action.</Pedantic rules lawyer>

So I'm still not convinved. I think this is one of those "Fate rewards those well prepared" moments, where "oh ****, why didn't I think of that before" isn't going to help you.

First of all focus power action it is an action used to manifest your power in combat (in this case it's a reaction). So if you cast any power not beeing in combat and get demonic possession I would say you can use "resist possession". When you are in combat, normally you can use reaction only in response to some event such as an attack. Usually in your turn nobody else is making anything except you, because it is your turn, opponets can do anything to you in their turn thats why they wrote, that you can use reaction when it is not your turn. But in this case the event to which you can respond take a place in your turn and I think you can react to it because you know the power which can be casted to resist possession and errata allows to use it even if another power was casted in this same round. But you will lose your reaction for this round if you cast it. But that's how I would rule it. If you look only on mechanic in combat, then you wouldn't be able to cast resist possession in your turn.

Rounds and Actions is just a mechanic of Detailed Time, which is not exclusive to Combat (Core book p187).

And even out of combat, you're still trying to react to something that has already happened. In combat, you don't dodge bullets, you move aside as you see the weapon being pointed towards you. You don't parry after the axe is stuck in your head, you parry as you see the blow coming in.

Trying to React to a Peril that has been caused by your own, previous action would be a bit like trying to defuse a bomb, and then trying to dodge after you failed and it detonated. Too late, m8!

I can see both sides of the argument, but I'm still not quite sure what the RAW actually is, here. Isn't there an email adress I can send rules questions to?

Darth Smeg said:

You are reacting to feeling the daemon clawing open the rift in the warp you failed to control while manifesting your power.

Think it in the same way you think of dodge, only with daemons.

Darth Smeg said:

You didnt' understand what I meant. When you sit in your room and trying manifest any power you don't need to know how long it takes to cast it: half or full action or reaction, cause if not in combat or if there is no enemy with whom you can compare your time there is no need to slice time to rounds and turns. The focus power time in psychic abilty descriptions means how long it takes to cast a power in combat! Check page 193 Core Rulebook on focus power action.

Imagine a situation: You fight with a demon, you cast a spell and get demonic possession result, you can't use resist possession with your understanding. Then miliseconds later demon fighting with you is trying to possess you and you can now use it? For me it is not logical. You should have this same chance to cast resist possession cause in both this cases you start casting it after you feel demon trying to mess with your head.

This is like you wrote: instead seeing blow coming in and parry it, think that the psyker starts to feel that something is trying to get to his head and possess him. For me it is no diffrence if it does a demon in his turn or a demon in a turn of psyker.

But if you look at the rules, then I agree you can only use this power as a reaction so you can't cast it in your turn only in a turn of a demon who wants to possess you. Unless you prepared and casted it before and it is working when you get perils of the warp.

"At a certain level of complexity any system becomes essentially unpredicatable, so keep it simple stupid." This is one I use at work when arguing against the fracken bureaucrats who think you can improve a system by adding levels complexity.

To put that in context, at any given point in time there are too many rules for one person to understand them all and how they interract.

But bugger it all Darth Smeg, you make some good points. I do agree with your rationalisation that it is better to be prepared. Now I'm second guessing my post. Good thing I'm not the gm and we don't have a psyker anymore (and my party doesn't have a psyker precisely because he didn't resist possession when he rolled demonhost mwha ha ha...)

Fortunately for us our gm tends to err in favour of the PCs in the face of ambiguity, bless his little cotton socks .

Zakalwe said:

Erring in favour of the PCs is HERESY!

Dakka-dakka-dakk!

@ Darth Smeg

I think my neighbours just heard me laughing at that, thank you.

p.s. Is 'dot no' Norway?

You're welcome, and yes, it is

I like to think of it less as a power (it being the sole and explicit exclusion to the "no more than 1 power a turn" rule) than as a mechanic meant to represent warp-enhanced resistance to possession attacks, and the potentially dangerous side effects of abrupt changes to the way the warp is channeled (from the original power to a divided attention and control).

Its sort of an ablative ability. It mitigates what could be (possession, which in-universe instantly begins to mutate you, amongst other horrifying things, not to mention leaves your body in the control of an entity of the warp... baaaaaaaaaaad. Very bad.) into what might be (nothing a majority of the time, with possible psychic phenomenon and rare perils).

It is there to help negate a worst-case-scenario with uncommon minor and rare major dangerous side effects. Unless you'd like a dozen rolls on the mutation table (assuming you can even get exorcised) and maybe TPK or get mercy killed, the risk is well worth the increased protection.