Peter BOSCO'S
Adventurer
Disclaimer - Answers may be broader than original question
Ranger - rewrite the basic Ranger to not have spells (and to be a bit more powerful). Include Expertise in Nature or Survival at Tier 3 and in both by Tier 4. Create sub classes that do have spells in a manner similar to Arcane Trickster and Eldritch Knight. Maybe add in a poultice based Healing ability on short rests, similar to a Bards Song of Rest? "Here, eat these herbs and you'll heal faster."
Wizard - Create new sub classes based on Implement choice. Make Wand Wizards (maybe INT bonus to Initiative) different from Staff Wizards (maybe INT bonus in Temporary Hit Points) different from Book Wizards (maybe faster Ritual Casting?), different from Orb Wizards (maybe roll 1d20 at the start of each day and let it replace other dice rolls, similar, but weaker than, to how Diviners how work?). Eliminate the more boring half of current specializations to make room.
Warlock - Require them all to have a Bond of Flaw (or both) related to their Patron. Otherwise fine as is.
Cleric - Eliminate the entire class, and make them all Warlock sub classes. Require them to have a Bond or Flaw related to their Patron, like other Warlocks. Let some Patrons provide Medium Armor Proficiency, just as some types of Clerics now get Heavy Armor Proficiency.
Druid - Eliminate Circle of the Moon as too powerful (just too much damage soaking with Wild shapes). Replace with another school.
Fighter - Mostly OK as is but Second Wind does not scale well enough. (Maybe it heals Half Proficiency d10's + level, not 1d10 + level?)
Monks - Rename as Brawler to kill any East Asian cultural implications and the confusion with European cloistered religious folk. Rewrite the basic "Brawler" to not have spells or Ki powers that duplicate spells. Create sub classes that do in a manner similar to Arcane Trickster and Eldritch Knight.
Bard - too powerful. Eliminate full caster abilities, cut to a three-quarters caster that starts with Cantrips only and tops out with 7th level spells. (Maybe steal some design ideas from Artificer?)
Barbarian - Name now politically incorrect. Rename to "Reckless Warrior"
or something similar and add fluff clarifying that they are not all from "barbaric" cultures, they just have anger management issues. Otherwise ok.
Sorcerer - Draconics +3 boost to AC at Level 1 overpowers all other Sorcerer (and maybe Wizard) builds at L1. Let it scale with level instead, maybe equal to half of Proficiency?
Rogue - Let them Sneak Attack with a wider variety of lighter weapons. It's silly to not be able to Sneak Attack with a club for instance. Maybe they can Sneak with any weapon doing a d6 or less at Tier 1, a d8 at Tier 4, and a D10 at Tier 4? (Maybe exclude Unarmed Sneaks to not step on the Brawlers design space?)
Paladin - Building a whole class on Smiting and then only letting them Smite on a 20 is bad design, as it creates a class whose power is too depend on rare dice rolls. Paladins should get the Improved Critical and Superior Critical Champion Fighters do (but maybe not with dual weapon fighting, that might be too many crits).
Ranger - rewrite the basic Ranger to not have spells (and to be a bit more powerful). Include Expertise in Nature or Survival at Tier 3 and in both by Tier 4. Create sub classes that do have spells in a manner similar to Arcane Trickster and Eldritch Knight. Maybe add in a poultice based Healing ability on short rests, similar to a Bards Song of Rest? "Here, eat these herbs and you'll heal faster."
Wizard - Create new sub classes based on Implement choice. Make Wand Wizards (maybe INT bonus to Initiative) different from Staff Wizards (maybe INT bonus in Temporary Hit Points) different from Book Wizards (maybe faster Ritual Casting?), different from Orb Wizards (maybe roll 1d20 at the start of each day and let it replace other dice rolls, similar, but weaker than, to how Diviners how work?). Eliminate the more boring half of current specializations to make room.
Warlock - Require them all to have a Bond of Flaw (or both) related to their Patron. Otherwise fine as is.
Cleric - Eliminate the entire class, and make them all Warlock sub classes. Require them to have a Bond or Flaw related to their Patron, like other Warlocks. Let some Patrons provide Medium Armor Proficiency, just as some types of Clerics now get Heavy Armor Proficiency.
Druid - Eliminate Circle of the Moon as too powerful (just too much damage soaking with Wild shapes). Replace with another school.
Fighter - Mostly OK as is but Second Wind does not scale well enough. (Maybe it heals Half Proficiency d10's + level, not 1d10 + level?)
Monks - Rename as Brawler to kill any East Asian cultural implications and the confusion with European cloistered religious folk. Rewrite the basic "Brawler" to not have spells or Ki powers that duplicate spells. Create sub classes that do in a manner similar to Arcane Trickster and Eldritch Knight.
Bard - too powerful. Eliminate full caster abilities, cut to a three-quarters caster that starts with Cantrips only and tops out with 7th level spells. (Maybe steal some design ideas from Artificer?)
Barbarian - Name now politically incorrect. Rename to "Reckless Warrior"
or something similar and add fluff clarifying that they are not all from "barbaric" cultures, they just have anger management issues. Otherwise ok.
Sorcerer - Draconics +3 boost to AC at Level 1 overpowers all other Sorcerer (and maybe Wizard) builds at L1. Let it scale with level instead, maybe equal to half of Proficiency?
Rogue - Let them Sneak Attack with a wider variety of lighter weapons. It's silly to not be able to Sneak Attack with a club for instance. Maybe they can Sneak with any weapon doing a d6 or less at Tier 1, a d8 at Tier 4, and a D10 at Tier 4? (Maybe exclude Unarmed Sneaks to not step on the Brawlers design space?)
Paladin - Building a whole class on Smiting and then only letting them Smite on a 20 is bad design, as it creates a class whose power is too depend on rare dice rolls. Paladins should get the Improved Critical and Superior Critical Champion Fighters do (but maybe not with dual weapon fighting, that might be too many crits).