Quote Originally Posted by Dr.Samurai View Post
Your suggestion is interesting but I'm not sure how it would work. Could you provide an example?
Here's a couple examples. First, some non-spell examples that can apply to non-casters.

You make an attack with a weapon. You use your INT to force the die roll to be a 15, plus modifiers, practically insuring a hit unless the enemy's AC is very high. But sometimes a 15 isn't enough...
You make an attack with a weapon. You have disadvantage because you are blinded, but use your WIS to choose the better of the two results, overcoming your disadvantage through superior experience.
You make an attack with a weapon. You roll poorly, so you use your CHA to reroll, getting a better result through sheer determination.

You run into some ball bearings and make a DEX save. Basically the same as above, but now applying to a saving throw instead of an attack roll.
You make an Athletics check to climb up a cliff. Halfway up, you need to make another Athletics check, and don't want to fall. Again, same as above, but now applying to an ability check.

You cast Disintegrate. You use your INT to force a 5 on the saving throw, practically insuring a failure, unless the enemy's save bonuses are very high.
You cast Disintegrate. The target has advantage on the saving throw because they took the Dodge action, so you use your WIS to choose the worse of the two results.
You cast Disintegrate. The target rolls high on their save, so you use CHA to force a reroll.

An enemy mage casts Dimension Door to escape, so you Counterspell. You use your INT to make the Counterspell check a 15 plus modifiers, but the enemy uses CHA to force a reroll, nullifying your 15.
An enemy mage casts Dimension Door to escape, so you Counterspell. You roll well on the Counterspell check, so the enemy uses CHA to force you to reroll. You use WIS to take your original result.
(Technically, the way I wrote it out, you shouldn't be able to use these abilities on someone else's ability checks, but I do think it should apply to Counterspell. I'm just not sure how to properly frame the rule to work that way.)

Basically, it comes down to:
[You/your target] makes a(n) [ability check/attack roll/saving throw] and [you/your target] uses INT to force the result to be [5/15]. [You/your target] uses CHA to reroll, nullifying the INT effect, so [you/your target] uses WIS to take the original result, nullifying the CHA effect.

Actually, the more I think about it, the more I like these. INT is kind of in the weakest position, since it needs to be used first. Everyone else can just wait for you to use your INT effect, then nullify it. But INT is pretty reliable when you do use it and it doesn't get nullified. CHA is in a pretty good position, since you can wait to use it until after you get a bad result, but a reroll isn't guarantied to succeed. WIS is interesting, because you generally can't use it most of the time (if the roll doesn't have advantage or disadvantage), but what it does do is let you clutch through those bad rolls more easily, making you more reliable in a tight spot.