I changed what the stats do, mostly to address the discrepancy between saving throws (being unable to hit very high DCs on non-proficient saves, and some saves being much more common than others), but also to reduce ambiguity (particularly between Intelligence and Wisdom, and what exactly a Charisma save is supposed to cover). The end result includes the following:
- All checks are made with a combination of two bonuses.
- PERCEPTION replaces WISDOM, as the linked stat for Survival and Medicine checks.
- MIND replaces INTELLIGENCE, but also covers the aspects of Wisdom that are related to intuition and understanding.
- SPIRIT replaces CHARISMA for the purposes of social skills, but it also takes over for Wisdom in determining divine spell save DC.
- FORTITUDE saves replace Strength saves and Constitution saves. Your Fortitude save bonus is equal to Strength bonus plus Constitution bonus. Proficiency isn't a factor for anyone.
- REFLEX saves replaces all Dexterity saves. Your Reflex bonus is equal to your Dexterity bonus plus your Perception bonus.
- WILL saves replace Intelligence, Wisdom, and Charisma saves. Your Will bonus is equal to your Mind bonus plus your Spirit bonus.
- Initiative is the one exception to the rule about adding two numbers together, since you add Dexterity+Perception+Proficiency.
Specifically for the balance of Dexterity, and to prevent anyone from gaining a bonus while dumping the relevant stat, there's no way to change the following:
- Strength is used to hit with melee weapons. If you're proficient, then you also add your proficiency bonus.
- Dexterity is used to determine your AC. If you're proficient in the armor you're using, then you also add your proficiency bonus to AC. Even in heavy armor.
- Constitution gives you temporary HP, that renew with a short rest. Armor adds to this value, instead of improving AC.
- Perception is used to hit with ranged weapons. If you're proficient, then you also add your proficiency bonus.
Following those rules, you're expected to build certain ways, in order to fit your character concept:
- Fighters can either go Strength/Con, and just accept that you're going to get hit (and nullify much of the damage with your temporary HP); or Strength/Dex, if you want to avoid getting hit in the first place. Most fighters should end up with decent scores in both Dex and Con.
- Monks are a subclass of fighter. They get a bonus to AC when using light armor and no shield, which means they'll probably go the high-Dex and lower-Con route. They're also still proficient with greatswords, so you can go greatsword+headbutt if you don't want to go the flurry route. Monks gain no benefit from Perception, Mind, or Spirit, aside from saving throws and initiative.
- Rogues are intended to fight at range, so Perception is their main stat. They probably want decent Dexterity, because they don't get heavy armor. If you want to play a melee rogue, then you need to invest in Strength.
- Rangers are a subclass of rogue, and don't have any magical powers, so all of the same advice applies to them.
There's more to it, of course. I had to change the weapon table in order to re-balance heavy weapons and light weapons, and that required a complete overhaul of some other numbers. There's nothing like GWM +10 to damage, but the relevant fighting style gives the equivalent of +1d4 at all times. A longsword in two hands is exactly as powerful as a greatsword; but the greatsword is heavy, and there's a feat that gives the equivalent of the barbarian's Reckless Attack, and it only works with heavy weapons. Piercing damage offers a slight benefit over slashing, in terms of better critical hits, but you can't use a rapier in two hands.
If that sounds interesting and you want to learn more, I recommend purchasing
Gishes & Goblins at DriveThruRPG.com. I've been holding off on advertising, until the print version is available, but it's already available in digital format.