No, my inner debate is about saving throw categories versus ability checks. The debate runs something like this:
- Saving throw categories are roll-over, just like attacks;
- ... But ability checks are roll-under, making survival easier in many situations, especially at 1st level.
- Saving throw categories allow for variation by danger type -- magic can be more dangerous than poison;
- ... But ability checks allow variation among characters: some will be better at dodging dragon breath or worse at resisting poison than others, regardless of class and level.
- ... But saving throw categories allow for variation by class, which means that fighters will find some things riskier than other classes would;
- ... But ability checks could have the same variation, with class-specific bonuses.
- ... But saving throw categories also allow for variation by level and improvement over time, with some classes improving much faster than others;
- ... But ability checks could again do the same thing, just by adopting the bonuses in Target 20.
- ... But if you're going to adopt the Target 20 type, class, and level bonuses, why not just use Target 20, keeping saving throws recognizable to a wide variety of people?
- ... But then ability variation is lost; anyways, some situations seem like they shouldn't be easier to resist with level.
I'll keep writing saves as "Con save" or "Dex save", though, because I will also allow a +1 bonus if the defender has a high attribute (4 or higher.) For unnatural attacks, the player's description of how the character avoids the attack can result in a further bonus. If a player throws a bucket of water right as a dragon breaths fire, it won't stop the attack, but it might be worth a +1 for a high Int.