So… There's a power. A relatively easy to use power. That has the ability to slay any mystery. Psychometry auto identifies people involved to the name, class, level, and random facts, all you need is some object, or an area.

We know the Imperium uses psykers in many applications… HOW IS THERE CRIME IN THE 40K UNIVERSE?

How are there Inquisitiors? Their identities and involvement in ANYTHING would be found out in a second. Not only does this allow players to kill mysteries with a single roll, ti allows the enemies to slay the players just as easily if you were trying for subterfuge.

Am I the only one who thinks automatically giving out that sort of information is ridiculous?

I think you overestimate this powers abilities as well as the number of Psykers who can reliably manifest it for long enough to learn the details you worry about.

First, the power itself. It states that " You sense the most recent strong emotion associated with the area—love, hated, amusement, fear and so on."

Now, unless the Psyker is first on the crime-scene, that emotion might very well be the violent fear or nausea of the witness who discovered it. Any strong emotion experienced at the scene will "contaminate" it, making Psychometric readings much harder (if at all possible).

But even if your Psyker was first on the scene, he would need to pass 5 consecutive power rolls to keep it going for long enough, and the 4 sustain-tests would not gain any benefits of Invocation. With a WPB of 4, you would need to reliably get 12 or more on the power dice, which means rolling at least 3 dice. Psy Rating 3 requires a Psyker of Rank 4.

Psykers are rare. Very rare. And those few that survive sanctioning are rationed and stationed like any other very rare and extremely valuable resource. They will be either on duty with the Guard, in the service of powerful noble or merchant houses with the pull to requisition one, or otherwise busy with Very Important Stuff™.

Your local enforcers do not have a Resident Psyker at the Presinct station. Not even your Arbitrator Fortress is likely to boast one. The planetary governor might have one at hand, to protect him against other Psykers. You know, to hide his presence from those very rare psykers who might want to pry into his affairs?

So there you have it. There's crime and murder everywhere because it pays, because the Imperium do not have the resources or will to combat it properly, and they most certanly do not have Psykers everywhere running around using their powers to investigate everything.

And even if they did, they wouldn't. For the simple reason that for every 10 power dice that are rolled, there is a Phenomena of Nastyness. And every 4 of those are a Peril of the Warp. Remember our example above, requiring 3 dice? Each manifestation of those have a 27,1% chance of causing 1 or more phenomena. Or a 7% chance of a Peril. (This is just the initial power roll, the rolls to sustain do not cause Phenomena. But of course, if you fail one of them, you have to start again)

Put another way, for every 100 crime scenes "read", there would be 7 Perils of the Warp.

Those are bad.

Almost 1 in 5 of those involve Daemons popping into existence, killing and creating havoc. So that's at least 1 Deamon for every 100 crime scenes investigated. Sound good? You know what happens when there are Daemonic incursions right? I mean, after you've called in every military body in the vicinity (Space Marines if you can!) and killed it? There is purging to be done! According to The Book of Judgement the proper punishment for Witnessing Unsanctioned Psychic Manifestation is Execution, witnessing daemonic incursions… burn the general area to the ground.

And that's just the extreme ones. You have things like reversing gravity. In a Hive, that can be… bad. Just think what might happen to that Arbites APC parked nearby. Those 4 tonnes of metal will rise between 3 and 30 metres (16 on average) before falling back down. Ouch.

Expensive. VERY expensive.

You know what they say, when the cure is worse than the disease?

This is what I stated in another thread with someone else who had similar concerns. Mind you, this is just my interpretation/opinion of the rules, and in no way is official. GM discretion is advised.

MY own campaign design thread, any thoughts welcome!

You ever remember seeing those movies with a person reading someones palm and giving cryptic warnings? It's like that, only more vague IMO. In none of the divination powers (besides Far Sight and possibly Soul Sight) does it ever allow you to explicitly know what the doom/peril/problem/fate is.

I'm going to post how I've worked Divination into my campaigns. This is just my interpretation of it, so bear with me.

Dowsing: You need tangible evidence in order for this to work. Obviously once you have this evidence, you should already be on the right track of who might be at fault. And this only works for a specific purpose of what you know, not "Who killed Roger Rabbit."

Far Sight: Only helps if you know the exact location or have been there before. This does not help you any if you don't know when the bad guy(s) will show up.

Psychometry: I have no doubt that death and fear are the strongest emotions. So, say you used Psychometry at a murder scene and stayed there for 50+ rounds. You have discovered the victim's emotions at his/her time of demise, facial features, occupation, and name. Or say you are in an unknown sorcerers den and are trying to figure out who uses the place. Anything could of happened there. A sacrifice, torture, ****, severe beating near death experience, 'so' not just the sorcerers feelings of power he felt there. You might have to be there for weeks or months sorting them all out. And who knows all the bad things you could attract while doing so.

Personal Augury: Subject must be willing. So say you use it on the Countess you are protecting and get max net success. As the GM you know that the Countess will soon be kidnapped and then sacrificed because her blood has the key to summon a daemon the mad General wants to talk to. A symbolic image could be copious amounts of blood being invissioned, she will be lost, and then a great evil will emerge. Something that could save her is an "eye." And to weave this into a sentence, "Countess Zariethial, soon you will be lost, a wound that will shed your life force will be inflicted upon you and then a great evil will emerge from your bosom, and the only thing to protect you is your eye." Note: Eye meaning Inquisition i. See how cryptic that is.

Soul Sight: Can use it on anyone, willing or not. Problem is, who/what is around that might know you are "casting" it, and would it be dangerous to manifest this power in this area? Meaning, who/what there would kill you on the spot if you use psychic powers in their presence? Other Psykers can detect, via Psyniscience, if you are using Psycic powers. Certain creates and familiars, technological and xeno devices, and certain daemons/warp entities can also detect Psychic Powers through various means. Yay for you, bad for the PC. Anyhoot, how does using it really help you know "Who Killed Roger Rabbit" a day, week, month ago? And, this power doesn't detect Sorcery powers. Unless you Houserule that, and I was always in favor of Houseruling that it only detects active powers anyhoot.

I don't have the rest of my books with me, but I seem to recall other powers in another book. Anyhoot, hope this helps some.

And as Darth Smeg stated (which is another important aspect) is the "Threshold" needed to manifest the power. So, psykers, utilize this power at your peril.