So, it's always been a house rule of mine that for any d% roll a 66 provokes one more d10. if that too is a 6, then something unexpected has happened. Something not always bad, but always trouble. I think it was borrowed from Call of Cthulu. It's caused things like grenades being a different payload then expected, a magic item being cursed or a recently-killed character coming back as a zombie without realising.

This is a variant of that, with a little more 40K. The Chaos Numbers.

When making d100 checks, a double 6,7,8 or 9 prompts a further 1d10. If you end up rolling three-of-a-kind, then the fickle forces of chaos have taken an interest in the action causing something unexpected to happen and complicate the issue. It will not turn a failure into a success, or vice versa.

66-6 Slaanesh. The prince of pleasure and keeper of secrets caresses the event. An NPC becoming incredibly attracted to the test-maker or a stray shot hits someone with useful information are examples of how Slaanesh can influence actions.

77-7 Nurgle. The lord of disease and filth corrupts the event. A bullet wound may become infected, a person develop an unpleasant itch or a sewage pipe spontaneously breaks over someone involved in the test.

88-8 Khorne. Blood for the Blood God! A wild grenade bounces into a crowded room, minor injuries bleed uncontrollably or a fight breaks out.

99-9 Tzeentch. The lord of change is mysterious, and none can hope to understand it's motives. Anything could happen.

So, what do you think? An interesting variant on critical failures, and when dealing with high enough scores they may even be mixed successes.

I like it. Perhaps link it to corruption points, or have particular effects on certain corruption (or insantity?) scores, say 6,7,8,9,66,77,88 and 99 points?

My only issue with stuff like this is, with a setting like 40k, enough bad stuff is already going to happen to me as a player that the DM tacking on one more thing doesn't really appeal to me. Because the universal rule of these things is that while it affects everyone NPC/PC in a world, the NPCs only see it once or twice before they are dead or leave the scene, PCs need to handle it everywhere all the time. There's no balance to it on the other end, you don't get 11: Smiles from Saint Drusus, or anything like that either, so it just, to me at least, seems a bit heavy handed.

the real trick if you want to balance this is to remember the holy number of the emperor, 13 (the 12 high lords of terra, and then the emperor)

off the top of my head, i would say that should the player role a 13 or 31 (inverse 13 to make it fair), then the emperor has taken interest in your actions

I was just guessing with the number, I didn't realize there was a holy one, I'm pretty terrible with the fluff of this world, a friend of mine is the one who knows it real well *He's been involved with this setting for over a decade, I've gotten about a year and a half*, I just work the numbers for him when he looks to run this system, so thanks for that clarification.

I do like the idea, although I wouldn't make any drastic events occur. I'd stick to minor strange annoyances, and keep the big hitters for the campaign.

These events would be minor events, things that won't ultimately influence the direction of the game, but may lead to interesting plot developments.

Say- if the acolyte's or explorers were trying to translate an ancient script, or dataslate, or there is visable text around the palyers, if they rolled the slaanesh event, perhaps the script becomes blurred, or the text manipulates itself into strange symbols. A successful willpower test will cause the text to return to normal for that player, if failed it will remain the same. The text is actually still normally viewed by others after the event, but a failed willpower will cause the text to forever be manipulated.

Well, as a GM I firmly belive in the old tradition of rolling a 1. (A throwback to my old D&D days) So I feel compelled to have fun with the pc's on a roll of a 95+

Of course, it also depends on the roll. If they get a 95 some minor annoyence occurs that bothers them, but isn't life threatening at all. But if they roll a 99, then the real chaos breaks out. My favorite example is when a PC tried to whirl around with a chainsword in a fight, rolls a 98 and kills the NPC crewman next to him In a spray of gore.

I really like the idea, though I share the concern of those who have stated that it may be a bit too much in an already perilous universe. My solution would be to have such numbers only come into play when the characters are traveling through the warp (the Gellar field does its job just fine until the players basically ASK for Chaos influence by rolling up the gods' number).