Spell casting risk and reward

I'm working on a campaign where magic has been tainted (similar to Dark Sun or Wheel of Time) and using it I has become dangerous. I'm planning on introducing a corruption value when a spell is cast, but I'd like to balance this out with a reward.

So my question is, would reducing the 8 hours rest time before you regain your used spell slots to just 1 hour be too powerful a reward. Keeping in mind that just casting a spell will potentially corrupt the casters soul...

If you think it's too good, I'm interested in hearing your thoughts on alternatives as well. Cheers.

I feel like this ranges from a useless reward to vastly overpowered depending on how you specifically run your game

I think this is very hard to do without wrecking a caster's sense of agency.

I don't know how good the reward is, if casting all your spells is just going to lead more corruption.

In general I try to stay away from screwing with major class features. But if you're going to do this, the rules should be clear, there should be other ways to be useful or avoid the taint.

Nobody likes spending their turn, should I do nothing or risk harm to my character.

How exactly is the taint being handled? Magic, in general, is usually pretty dang powerful even without any incentive to use it beyond "it's freaking magic" after all.

I've run a game with a similar premise to it and had the "taint" type deal be a caster level check each time a spell was cast. Lower level spells were pretty easy to pass and would rarely if ever cause a corruption, but the higher the spell level the exponentially more likely it became up to 9th level spells ALWAYS causing a corruption by their very nature of being too powerful for mortal hands to wield. Spellcasters did get help in that they could cast normally 1-action spells as a full round action to get a bonus on the check to avoid corruption, themed as them taking more time to focus and avoid casting it 'wrong'.

I'm plotting a game where magic is actually pretty badly wrecked. It's become dangerous and unreliable to use because of a recent magical war where spells of mass destruction were used.

However it's going to be a bit pulp in feeling, strange races (all races will be ~20 point racial points), mad max style vehicles, and polluted magic. There are ways to resist the taint (such as channeling it into your familiar first or using alchemy to resist it) but the use of traditional magic is going to be quite dangerous.

As a result I'm looking for a way to give pure spell casters a bit more.. rather than simply replacing spells (might as well play a partial spell caster) or making them immune to the taint (making the taint less relevant), I'd prefer to give them more bang for there buck. What's the saying, burn bright, burn quickly? With great risk comes great reward is my thought process.

As for how the taint is being handled, I'm currently looking at a variation of the insanity rules from horror adventures triggered as a corruption attack every time a spell is cast. Although I'm trimming it and simplifying it a little so it doesn't require a dice roll every spell. I'll post the full rules when I'm happy with my first draft..

You could always make a custom corruption, like the ones in horror adventures, specifically related to casting spells. That way, every risk would have a reward as well.

You could add in a manna system as well... casters could get a boost by spending more manna to make the spell more powerful than "normal" with the same risk instead of elevating the risk.

Or you could elevate the risk as well, or make the manna expenditure lower the corruption risk.

Lotsa different ways to go.

Its hard to say how powerful the advantage is if we don't know what the disadvantage is. For the current advantage it seems pointless unless you frequently give very short periods of rest instead of letting people sleep eight hours.

You should also figure out how players would react to it before trying to implement it though since if they suffer from "too good to use" syndrome they might only be casting spells in combat when its absolutely necessary, doing nothing otherwise or refuse to play casters in the first place making this kinda pointless.

Also if you do go through with it remember to make NPC spellcasters act like people who are worried about the corruption rather than units that died at the end of the encounter since other mages spamming spells when you can't will be jarring.

(for anyone who doesn't know too good to use syndrome is when something is rare enough or risky enough to do the player will never use it. )