So I stole a concept from Graver for the last mission I subjected my players to.

Graver once said:

Their fourth mission was cleaning up after a psyker from another cell screwed up and got "warp whispers". It was up to the PC's to head up investigations into who had been in the area at the time and to help the kill-squad track them down. They didn't ever go in with them for the kill wanting to keep their hands clean of the blood of women and children but they still got to see what happened to innocent citizens who were just suspected of being in the wrong place at the wrong time: wrong place being any where near a psyker and wrong time being any time the psyker gets it in their head to use their powers.
Having to point a kill-squad at women, children, screaming men, and everything in-between, seemed to do the trick and help the psykers player understand her responsibility.

Well, I had them go in and be the Kill-squad too.

I include the mission briefing as inspiration to other evil GMs

+++
Dicasterum Summation Report
Source: Caughran Heights, Sublevel 17, subsector Ligia, Scaxinad, Sibellus
Subject: Warp contamination
Summary of occurrence:
Reported occurrence of Class II Phenomena in populated zone. Collateral effect after psychic application of sanctioned technique by *Redacted*. Secondary information indicates probable moral threat. Assessment: Requires containment.
Time of incident: 804.817.M41
Scope: Event occurrence in proximity of Boiler Room, a local drinking establishment. Likelihood of event extension to cover nearby alms house, hab block and effluence pump-station. Estimated count of subjects at 15-30.
Location of incident close to Arterial XIII, increasing possibility of long-distance consequence spread. Minimum collateral response required, effect of large-scale citizen unrest unacceptable.
++++

In the end they posed as a team of medical investigators, and got the affected people (a lot more than the estimated 15-30) on "medication" (read poison).

While the session was good fun, my goal was to hammer in a sense of responsible-power use into our Psyker-character, who has a very cavalier attitude to risk and consequence, and has caused many a phenomena in all sorts of places.

It hasn't worked.

I also hoped this would be a shocker for the others in the team, who might perhaps be more inclined to keep the Psyker in line. But no.

They are all fairly hardened and Jaded by now, so they managed to escape any mechanical effects (No Insanity Points, boohoo), and are using some pretty atrocious "big picture, ends-justify-the-means" arguments as to why their characters so not consider killing 100s of civilians "no big deal".

While in line with the justifications of an Exterminatus, I'm thinking there should be some serious role-playing considerations when playing people who can happily murder 100s of women and children because "it is necessary to protect the Imperium of Man".

Thoughts?

I think your players are not doing anything wrong in regard to their PC´s attitude.

Their PC are the product of their surrounding which is the Imperium of Mankind. If the fluff does one thing, then it is bombarding us with all this "Innocence proofs nothing" "Kill the many to safe the [iNSERT]" "Better purge a 1000 then risk the contermination of a million". I always wondered why adventure designers of DH missions even EXPECT any player character to be mindfull of a single human life... or a dozen or a score. The character base versions are trained killers (Assassine), religious fanatics (Clerics, Sororitas; most stuff from BoM), emotionless half-machines (TEch-Priests), crazed warp-users and jaded nobles/buerocrats. I am happy that my players simply try to be different and are more "self-risking" and try to "safe them if you can" but the way the background of this game is...well, "it is on!".

@The Psyker goes on as usual
Since neither the player nor the PC have a moral dilemma the only reason for the PC to stop this would be that the PC himself would be taken responsible for his actions. This could either be done by his own Inqusitior, ringing him in ...or by said Witch-Hunter both of us know.

No, seriously. If you do not want him to go on about it you will need to come up with something with direct consequences to him. A very simple solution would be "degradation". Since he cause trouble, the Inquisitor decides to treat him in regard to "funds/payment" like he would be a number of ranks lower. Or make him wear a painfull penance shirt or both or that and something in addition to this.

IF the Inquisitor frones upon this. Again, I could very well imagine that the =I= are okay with it if the Psyker can reason that this was necessary. Good change for a Roleplaying moment when the Psyker is summoned up in front of a council made of his own Inquisitor, A Witch-Hunter and some other Inquisitor (third party, supposed to be "more neutral") where he is cross-questioned and needs to explain the deed. The other PC might be called forth as well to answer question regarding THEIR view of the situation while being threated by the Witch-Hunter that if they are found "covering a culprit" they will end with the same punishment that is dealed to him (IF found guilty).

THIS would be fun solution, me thinks.

I like it!

And wouldn't you know, but they already have a witch hunter after them

I agree that nobody frowns upon the purging of the many to secure the countless, but my problem is that neither the play nor the character seems to think that this should make him use his powers sparingly.

Why use Seal Wounds if a regular medica test will get them on their feet? Why use a psy-power to execute som nobody if a lasbolt to the brain will do just as well?

Now he knows that there are potentially catastrophic consequences whenever he uses a power, and that the Inquisition will have to expend resources containing them, but he just shrugs and says (like you indicated) that unless his superiors tells him to stop it, he wont.

Darth Smeg said:

I hope that my Moritat Assassin could do that, and do it with ease

I've got to say that Acolytes not really caring that they have to kill some 100+ innocents to prevent a possible spread of corruption don't seem all strange to me and it will probably be the expected respson from people in their positions - and the further they remain in the employ of the Inquisition the more jaded they are likely to become.

On the issue of the psyker on the other hand you may want to remind him that even if he don't care all that much how he throws his powers around there are alot of other people in the Imperium who do, and psykers are after all as a rule not loved by the majority. Hence if this guys goes over the top I wouldn't put it past the possibility that he gets a death warrent on his head by some Imperial agency or possible even their own Inquisitor who don't like to have loose cannons around that can be tied to him/her.

Well, my point (which I am obviously failing miserably to state) is that while collateral damage is acceptable, it is not desirable. As such it is the duty and goal of all honest servants of the God Emperor to take all practical steps to reduce collateral where possible.

Sure, we need to amputate the hand to prevent the limb from rotting. But what if it was in your power to prevent the hand getting infected in the first place?

+++Life is the Emperor's currency, spend it wisely+++

If not for moral reasons, then for purely practical reasons: Such containment operations consume time and resources that the Inquisition could spend more productively in combating the enemies of the Imperium, rather than on killing the citizens of the Imperium.

HI Darth,

as you already acknowledge it yourself: it seems that the boss has to talk to the servant in regard to his job description . This can be as heavy handed or as friendly as you intend. There are simply people like these around who will not stop something unless there are personal consequences. If the Inquisitor in questions has a dislike for this, he and/or his interrogator will sure take measures to make their displeasure known.

Darth Smeg said:

In that case I think that most likely the easiest way to hammer the point into the characters/players is to have their Inqusitior slap them on the fingers for their actions, maybe force them to make penance in a monestary or refuse to give them more fun toys due to their lack of restraint and precision in their work. It seems to me that you may need to go a bit harder than only hinting at stuff. But I could of course be wrong.