D&D 5E Str, Int and Cha Saves

[JoshR]

Str - spells that seek to physically restrain the target (breaking/escaping a resilient sphere, evard's black tentacles, web, perhaps certain wall spells)
Dex - spells that can be avoided via quick reaction (AoE such as fireball and lightning bolt)
Con - spells that attack the body (Disintegrate, Cause Disease, Polymorph)
Wis - spells overcome by keeping a cool head or "grip on reality" - fear, insanity (this would make clerics good vs. fear, falling back on their faith in a deity)
Int - illusions
Cha - charms and domination

I'm very tempted to use exactly this system as a house rule, but I'm concerned about possible impacts on game balance. Does anyone have any thoughts on what the impacts would be (for good or ill)?

 

[Stormonu]

The link in my previous post had some discussion on its effects if used - primarily that it can make spellcasters more powerful if they can tailor their list to target an opponent's most likely lowest save. , and the reverse is true of a DM inadvertently (or purposely) hitting characters in their weak spots more often than is the norm.

 

[Daern]

Saves or Skills

The more I think about this, it really asks the question, "What's the difference between Saving Throws and Skills?" It makes sense to say that Saves are Reactive and Skills are proactive, but there are a lot of situations where they overlap.
If a character has Acrobatics but not a Dex Save proficiency, it doesn't make sense to require a Dex Save to mitigate damage form falling into a pit...
Similarly, asking for an Athletics check when a character has a better Strength Save to escape a pile of rubble is similarly dissonant.
Skills that could be used as Saves might include Athletics, Acrobatics, Arcana, Investigation, Religion, Perception, Nature, Survival and Insight.
Maybe a Rule-of-Thumb/Guideline would be, "Use the most appropriate number." Conveniently, the numbers are the same!
However, this slips into territory where which Save or Skill to use becomes a negotiation. I've encountered this a bit because of various houserules I've used for DCCrpg, and it can be unsatisfying.
Hmmm.