Help with Pact Magic: Corruption rules.

[faustin]

PM is probably the coolest magic system in D&D. Summoning and bargaining and be possesed by dubious Outsiders entities for power? YES PLEASE!

My frustration comes with the lack of risks or consequences for such deals.
Inviting Acererak the Devourer in? You just may become pale and a bit more power hungry. Focalor, duke of Hell? Emo all the way. And there are even mechanics for suppresing physical or mental tells.

Pretty tame stuff, which doesn't explain why in the original Tome of Magic Pact Magic was mistrusted as best and persecuted at worst.

I was hoping to incorporate some Corruption mechanics like the ones for Patrons in DCC. Having your body and mind warped by your host, which may be a former powerful necromancer, devil, conqueror, etc..looking for a ticket back from the Void, is one hell of a reason for which most people don't want to risk meddling with the stuff and will kill you on the spot if you do.

Problem is, I'm kinda of a noob for such things.
Could anyone lend me a hand, or at least a few hints?

[Onos]

Well, since Pact Magic is build to be balanced as-is, any sort of Corruption mechanic will need to provide bonuses as well as penalties. Although being used with just the penalties could be pretty cool in a non-caster campaign to restore magic to the world or something. Anyway. Generally speaking any Cons from PM can affect more or less anything on the character sheet, so long as some in-world justification is given.
Like a GOO Warlock could quite reasonably expect to take Cons in any mental stat, particularly Wisdom, but with a variety of handwaves (channelling too much power through a mortal body, eldritch forces, because the Patron felt like it) you could stick any sort of Con anywhere. Pros on the other hand should generally stick to the existing strengths and themes of the class/subclass.

But the first step for this sort of thing should really be determining how severe you want your Corruption mechanic to be and how easily you want it to be applied i.e. will this cap at small numerical penalties and situational disadvantage or go all the way up to burning the character sheet (or somewhere in between), and will it be a gradual build up over several sessions, possibly culminating in a major plot point or is this something seriously dangerous to play around with that can have a major impact with a single spell (or again, in between)?

You'd also be looking at creating a core Corruption mechanic in addition to a subset with specifics corresponding to each Patron, as well as with each Pact if you want to take it that far. Once you have a sketch in mind for all of that you'd create the Pros to help balance out the inherent weakening of the class. Obviously Pros can vary hugely, in a sort of Call of Cthulu style game or if the whole party are warlocks you might be fine to keep it minimal or non-existent so it's probably a good idea to determine what sort of game you'll be running before you do any major legwork. You could just go straight for the Cons and address the Pros on a case by case basis with each game you use the Corruption mechanic in.

[faustin]

Good thinking. Also I was considering to divide between fixed pacts (stipulated benefits and duration) and going wild (using vestiges beyond your level, keeping them for too long, drawing too much power, etc..).

In theory a binder who keeps playing safe all his life doesn´t have to worry about corruption... much. Of course the life of an adventurer is anything but safe, and risking your body and soul may be the only way to make it through.
Be ware however, as it may come the day when the thing looking from the other side of the mirror is no longer you.

[Onos]

Good thinking. Also I was considering to divide between fixed pacts (stipulated benefits and duration) and going wild (using vestiges beyond your level, keeping them for too long, drawing too much power, etc..).



Well again, that's something you could change from campaign to campaign but it's definitely easier to manage players at the table and prevent crazy shenanigans if you stick with fixed pacts. It can be really fun to go outside typical level-scaling for abilities but it does obviously come with the risk of your players crushing encounters (or themselves if they misjudge the riskiness of a pact).

I'd recommend escalating penalties for keeping pacts beyond their recommended duration and for having "extra" pacts beyond a soft cap determined by level. Let's say half of proficiency bonus for example: this gives us a ballpark estimate for power of pacts, and allows us to set a hard cap equal to proficiency bonus but you would take extra penalties beyond those listed in the specific pacts you've made.

Con and Charisma seem fairly thematic for strain related penalties for pact corruption, so let's say each Pact you have beyond your soft cap (half proficiency) inflicts -1 to your Con and Cha ability scores. Although this is probably a good place to mention exponential penalties, which are very thematic for corruption but create a potentially very risky play style. Again, something you'll want to decide on depending on your table specifically, and we'll revisit this particular area later but it's a good idea to have rough ideas in place so you know what your constraints are.



In theory a binder who keeps playing safe all his life doesn´t have to worry about corruption... much. Of course the life of an adventurer is anything but safe, and risking your body and soul may be the only way to make it through.
Be ware however, as it may come the day when the thing looking from the other side of the mirror is no longer you.



Excellent, this sort of theme allows a decent level of granularity to the extra system you're adding. You could have each Pact with a minor and major bonus; with the penalty kicking in if the major bonus is used, or alternatively having a corresponding minor and major penalty.

Something you'll want to decide early on is what your Corruption track will look like. By this I mean is your penalty for each Pact generating Corruption points and you have some sort of Bad Thing happen as you reach certain thresholds of Corruption points, or will each Pact have its own individual penalties which are all tracked separately? Pros and cons to each, again for something like this I'd try to find whatever approach matches your theme best and work the mechanics from there.

Oh, do you want it to be possible to remove/reduce the effects of Corruption and if so how difficult do you feel it should be? That's something which will heavily influence the risk-taking behaviour of your players, as if it's easy to manage they may end up "yo-yo Pacting" whereas if it's literally impossible to remove and not an extremely integral part of the campaign they may simply avoid it entirely.