D&D General Decoupling Ability Scores from Offense

[NotAYakk]

With stats mattering less, you could even do this.

Ability Score Increase
Pick a feat. If it grants +1 to an ability score, instead grant +2. Then pick either 1 other ability score you did not already increase this level, and give it a +1.

Doubling the half feat ability score boost reflects that +1 dex is worth less with ability scores worth less, so it makes them equal.

Granting ability score increases even though you get a feat also reflects the fact that ability scores are less important.

A neat side effect is that the ability score you focus on, you also end up with other mechanical associated benefits. So you usually aren't just "I have 20 dex that is a +5", if your dex is 20 you probably also have a bunch of dexterity-related abilities via feats.

 

[Li Shenron]

It would be a very different edition, but what do you think?

I think it would be fine, and you could start experimenting with a single change so that it wouldn't be a very different edition:

"Replace your ability bonus to any attack roll with your proficiency bonus"

That's it. This means that anyone proficient in a Str/Dex weapon will roll d20 + 2x prof, instead of d20 + Str/Dex + prof, while a nonproficient character will roll d20 + prof instead of d20 + Str/Dex.

The numbers won't be exactly the same as before because abilities bonuses go from -5 to +5, and prof goes from +2 to +6, but a blunt comparison is misleading. Most character who intend to use weapons already have at least +2 when starting and usually want to higher asap, so maybe fighter-types will lose something in the waiting for prof increase. On the bright side, they don't have to invest everything in those stats.

Characters with a low score will benefit from this but that's kind of your purpose. The difference between being proficient or not however is the same. So even if the Wizard is suddenly much better with a Str weapon than before, it's still more convenient to cast spells and let the fighter-types fight.