Having a read of the rules in the Core book, corruption points seem to stack up at an alarming rate if theres any sorcery/daemons within 50 light years of the player. Possibly an exaggeration, but lets see.

(Basically what Im looking for is how people handle situations where players are at risk of Corruption Points. Ill say what I think the text is implying and ask for any clarification if Im not sold on any one meaning. PLEASE disagree with my interpretations and supply your own, the more perceptions of these rules, the better IMHO)

The suggested scenarios are as followed:

Warp Shock
Fail a fear check against a daemonic entity, gain its fear rating in corruption points.

I like this, its straight forward and makes perfect sense imho.

Rending the Veil
'Characters caught in a full-blown intrusion of the warp into corporeal reality gain corruption points from the experience.'

This one seems ambiguous. Does that mean if you see a daemon walking down the street, you gain corruption points? Would you take CP from seeing a daemon burst into reality and then some more for the sheer fact that your looking at a daemon even before its fear comes into effect?

Sorcery
'The practice of sorcery, witnessing dread rituals and invoking Daemons are all causes of Corruption, regardless of the reason.'

Okay this ones fairly simple again. Take part in a bad ritual, gain corruption. The witnessing part seems to give DMs a nice bit of wiggle room as to whats considered 'Witnessing' and whats 'Busting up cultist activity with Flame and Bloter'

Blasphemous Lore
'Knowledge itself can corrupt, and the study of certain tomes, pict-logs and even some debased artwork can cause Corruption in the viewer.'

Sounds interesting, sounds like you could really mess up a player with this (which is kinda the point of DMing DH, right? =D )My opinion would be accidental knowledge should only add a small number of CP while actively searching for darker knowledge should have more.

Dark Deeds

'Evil acts done in furtherance of a malignancy or in pursuit of forbidden lore, or done to appease a Daemon always cause Corruption Points.'

Does what it says on the tin really. Though what can be considered 'Evil' can be very subjective.

Vile Persuasion
'Many Daemons and cult leaders are masters of insidious temptation and of sowing the seeds of doubt in a faithful heart. Their words and arguments can corrupt where force alone would fail.'

So is this with every word? Could a Daemon spout some Taunt in combat and as a result add corruption to the players? Could even cultists do the same thing?

And what about telling the party? Do people keep secret track of corruption points their party gains so that they dont know the local Cleric is corrupting them to Slanneshs fold, so that they dont reolise whats going on. Or every 2-3 session hand out 'secretive' CPs that they have gained so they know somethings up, but cant run to the Church and blow open the Clerics head 'because'.

As a DM, I find it very enjoyable to portray seriously corrupted characters who believe they are sane and who try to convince the PCs to accept their twisted worldviews. Through practice, I've found that I can argue a heretic's (crazy) point of view fairly convincingly. This is a great opportunity to dole out small amounts of Insanity and Corruption -- if the players pause to think about the heretic's words, they stand a greater chance of slowly falling to Chaos.

Take a priest of Nurgle as an example. That cultist used to be a devout worshipper of the Emperor, but when his wife and kids died from plague He did nothing to save them. When the man caught plague himself, the only one who answered his prayers was Grandfather Nurgle. When confronted by the PCs, he relates his story, asking them if they would have done any differently under his circumstances. Humanizing enemies like this can sometimes be difficult (it's hard to relate to a Khorne-worshipping Cuisinart-on-legs), but I find it makes for very enjoyable role-playing moments and final confrontations.

Tempting my players with rewards at the cost of Insanity/Corruption also works well. The Tech-priest character recently found a nice mechadendrite on the body of an engineseer who died defending a ship's blessed plasma engines. I allowed him to take the cybernetic but gave him some Corruption as a consequence of such sacreligious looting. The data banks cataloguing a radical Magos's experiments might contain much useful information, granting important leads in the investigation or discounts on the purchase of Lore skills, but reading his notes is disturbing and causes Insanity gain.

Generally, I feel it's a good idea to give players some way of resisting Corruption and Insanity accumulation. When dealing with warp rifts, horrifying revelations, conversations with cultists and other events that aren't directly caused by the PCs actions, I typically allow Willpower or (occasionally) Toughness tests to mitigate or eliminate Corruption and Insanity gain. The test may be very difficult and/or not completely prevent the gain in particularly serious situations, but at least the players have a fighting chance to resist. If the players choose to pursue a damning course of action (looting the engineseer's mechadendrites), I don't allow such tests -- they made the decision, so they will suffer the consequences. Slapping them with a hefty dose of unavoidable Corruption (whoops, a warp rift opened, take 2d10 CP) is unfun and can make the players feel cheated.

The manner in which you award IP/CP is really a matter of preference -- the above are all methods I personally like to use.

CP accrues fast if you want it to. I've never been in a campaign where CP accrued faster than IP. I've been in campaigns where CP wasn't a factor at all. It just really depends on what challenges you throw at them and how you choose to implement the intentionally-ambiguous "gain CP" rules.

"Rending the Veil

'Characters caught in a full-blown intrusion of the warp into corporeal reality gain corruption points from the experience.'

This one seems ambiguous. Does that mean if you see a daemon walking down the street, you gain corruption points? Would you take CP from seeing a daemon burst into reality and then some more for the sheer fact that your looking at a daemon even before its fear comes into effect?"

I would give IP for just seeing a daemon walking around. I'd give CP if you were near a warp intrusion. Merely seeing one I would not give CP. Fear effects cause IP, not CP.

"Sorcery

'The practice of sorcery, witnessing dread rituals and invoking Daemons are all causes of Corruption, regardless of the reason.'

Okay this ones fairly simple again. Take part in a bad ritual, gain corruption. The witnessing part seems to give DMs a nice bit of wiggle room as to whats considered 'Witnessing' and whats 'Busting up cultist activity with Flame and Bloter'"

I think "witnessing" should be interpreted as "silent participation," not "watching it to wait for the perfect time to strike." Unless, of course, the ritual has some gruesome or otherworldly effects going on which might wash over all the participants.

"Blasphemous Lore

'Knowledge itself can corrupt, and the study of certain tomes, pict-logs and even some debased artwork can cause Corruption in the viewer.'

Sounds interesting, sounds like you could really mess up a player with this (which is kinda the point of DMing DH, right? =D )My opinion would be accidental knowledge should only add a small number of CP while actively searching for darker knowledge should have more."

This also goes to how much you want to **** on your lore-monkey. Gaining CP from every Forbidden Lore check is overkill and frankly, not fun from the player side. I would give CP when you get like 3+ DoS related to FL Warp, Psykers, Daemonology. Learning deep depths of crazy stuff from FL might also be worth IP if it's extremely jarring and horrifying - the details of the Pilgrims of Hayte and their reach, for example.

Dark Deeds
'Evil acts done in furtherance of a malignancy or in pursuit of forbidden lore, or done to appease a Daemon always cause Corruption Points.'

Does what it says on the tin really. Though what can be considered 'Evil' can be very subjective.

Murdering some dude on the street for fun doesn't give you CP (or shouldn't). Setting up a ritual sacrifice would. "Evil" in this case was a stupid word to use. What you're looking for is stuff that blatantly helps or invokes Chaos. Not every serial killer is running around with lots of CP just because Khorne likes bloodshed.

"Vile Persuasion
'Many Daemons and cult leaders are masters of insidious temptation and of sowing the seeds of doubt in a faithful heart. Their words and arguments can corrupt where force alone would fail.'

So is this with every word? Could a Daemon spout some Taunt in combat and as a result add corruption to the players? Could even cultists do the same thing?"

I would advise against interpreting things that literally. Here you're looking for false words convincing a true heart. When a character knows in some way that the words being preached to them sound wrong through the lens of the Creed but go along with it anyway. A random Taunt, I don't know. This is a lethal system but having to constantly replace characters, both as a player and as a GM, gets old fast.

"And what about telling the party? Do people keep secret track of corruption points their party gains so that they dont know the local Cleric is corrupting them to Slanneshs fold, so that they dont reolise whats going on. Or every 2-3 session hand out 'secretive' CPs that they have gained so they know somethings up, but cant run to the Church and blow open the Clerics head 'because'."

It depends. Do players usually have access to each others' character sheets in your game? If I was GMing and an event that proc'd CP occurred, I'd publicly say to the player "take X amount of CP." The other players shouldn't be allowed to metagame this knowledge though. They have no way of knowing in-game without corruption beginning to manifest itself (mutations, malignancies, etc). The OOC/IC line is important to enforce. The fact that the player knows their character is gaining CP does not at all mean that either the victim character or any other character knows. Enforce the in-setting cause-and-effect link. Have them investigate. If lots of people in the church start acting deviantly that's something to follow up on. If they don't find anything, then the cancer will grow. Such is 40k. Metagaming is way too easy an out.

Thank you Kshatriya for that in depth response =D

Blasphemous Lore

'Knowledge itself can corrupt, and the study of certain tomes, pict-logs and even some debased artwork can cause Corruption in the viewer.'

Sounds interesting, sounds like you could really mess up a player with this (which is kinda the point of DMing DH, right? =D )My opinion would be accidental knowledge should only add a small number of CP while actively searching for darker knowledge should have more.

The Ateanist book of perfection is a great example of a corrupting tome of knowledge. That tome is an almost literal gateway to the realm of slaanesh, which can only be observed through fervous study and decoding it's work. Knowing about it's existence or a brief giest of it wouldn't envoke corruption, for instance.

In contrast, the acolytes could stumble on a tome such as the 40k equivilent of the Necronomican, which by simply reading it opens the Acolytes minds to the eldritch horrors from beyond. That sort of tome qualifies here as well.

The difference between "evil" acts like killing and EVIL acts that provide corruption is intention if you commit cruel acts just for the sake of it then yes CPs all round, if you are being callous and cruel to serve a (for want of a better word) "good" cause. Then no, but maybe you shoud get some insanity from guilt and remorse down the line.

In other words: gunning down cultists without a second thought in the name of the emperor is fine (well it's an appalling waste of human potential but you know what I mean,) they are your enemies.

However, if you go around stapling suspects to walls with a harpoon launcher and needlessly prolonging their suffering by performing vivisection without asking any questions just because you hate them and want them to know it before you allow them to die and it's is definately Corruption time you Druchii wannabe.