My 6e would be... a heavily modified 5e.
Design principles is to make running the game at the table as easy as possible. So focus in support for In Person Play.
Fixing Rests:
A good night's rest gives you 1hp+Con and the lowest spent spellslots / or 1 mana + spell casting ability modifier.
Add more health potions and Mana Potions to the game.
More grittyness, more longer lasting impact of battles. Not this unrealistic and game pacing destroying 100% reset after each long rest anymore.
Fixing 5-minute work days and battles being front-loaded:
Battle Rush Dice: At the end of your turns in combat you gain a battle rush die (d4) up to a maximum of your Proficiency Bonus. You can spend battle rush dice to add to Attack bonus, saving throw dc, damage roll ...
So, the longer you wait to use your big abilities in combat, the more effective you can make them.
Fates Favor:
After you finish a combat (or a difficult non combat encounter determined by the dm, your Battle Rush die increases to the next higher die (d4 --> d6 --> d8 --> d10 --> d12 --> 2d6. A rest resets the die to a d4.
Fate favores the bold. The more you push instead of resting, the stronger you get in combat.
Fixing Spellslots:
Switch to a Mana based system for Wizards and Sorcerers.
Fixing Spellcasting (especially Wizards):
Spells are now gated behind proficiency and expertise. A Wizard need proficiency/expertise in a school of magic to be able to learn and spell of a certain level from that school. Turn some subclass abilities into spells and add some spells to even out spell schools, so you only need one wizard subclass for all schools of magic(gain expertise im one school of magic).
Bards become a wizard subclass.
Also Make Warlocks to something that is really a warlock, not a cleric with an outsider god-replacement. A warlock looks for Power everywhere, so it is a feat based classes (basically everything in that class is an invocation, giving access to different Branches of Invocations (Wizadry, Witchcraft, Alchemy, modyfying your body ...)
Fixing Skillsystem:
More granular 6 tier Skill proficiencies.
Untrained (no Prof. Bonus, roll with disadvantage
Familiar (no prof Bonus)
Practised (0,5 PB rounded down)
Proficient (PB x1)
Skilled (PB x1,5, Skill perks)
Expert (PB x2, additional skill perks)
Master (PB x2,5, Capstone Skill perk)
Also add levels of succes/failure (succed by 5, 10, fail by 5, 10) for checks.
Fixing encumbrance and tracking of ressources (Food, Water, Arrows ...):
Switching to a slot based abstracted system that is easy to use at a table.
Fixing Species/Race/Backgrounds:
Characters are created by choosing five life ingredients, outside of the class:
- Bios (Species) – Your biological nature.
Grants creature type, physical traits, and 1 Major + 1 Minor biological trait.
- Upbringing – Where and how you grew up.
Defines social background, a small feature, and languages.
- Vocation – What you did before adventuring.
Provides a skill or tool proficiency and a practical feature.
- Hobby – What you do for yourself.
A personal interest with a light, flavorful perk.
- Adventure Spark – Why you adventure.
When you act in line with it, you may declare Heroic Inspiration once per long rest (DM approval).
Mixed Heritage:
Characters with parents of different species choose a Major Trait from one Bios and a Minor Trait from another, with age, size, and type blended.
That are the biggest changes so far, and I have them all worked out already, just need to put them in the 5e2024 CC SRD and can start my own game ^^.
Edit: Forgot a more granular non magical gear progression and breakable weapons and armor.