Taking ideas from D&Dnext's playtest of Fighter, I thought of this homebrew rule applying to martial and half-caster characters (Artificer, Barbarian, Fighter, Monk, Paladin, Ranger, Rogue)
First off, the following subclasses get removed:
- Artificer: Artillerist, Alchemist
- Barbarian: Berserker, Bear Totem
- Fighter: Champion, Battle Master
- Monk: Open Hand, Long Death
- Paladin: Glory, Vengeance
- Ranger: Hunter, Beast Master (Both versions), Monster Slayer
- Rogue: Assassin, Scout, Thief, Mastermind
In place, all classes get these features:
Battle Master: At 1st level, you gain the ability to make various attacks, allowing you to aproach any challenge with various tactics. You gain a number of warmaster dice equal to your level, and in addition, learn up to two battle maneuvers. You can expend warmaster dice in order to perform these maneuvers. Some of your maneuvers require your target to make a saving throw to resist the maneuver's effects. The saving throw DC is calculated as follows:
Maneuver save DC = 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice)
The number of maneuvers you learn increases based on your level. (The idea is to get two maneuvers every two levels).
You regain all expended warmaster dice at the start of each of your turns, or whenever you finish a short or long rest.
(Maneuvers may include the generic ones that already exist in battlemaster, or some homebrew ones, as well as reworked versions of the class features from the removed classes.)
Critical Surge: At 2nd level, you feel an attunement to the ebb and flow of battle, knowing the best chance to strike at the enemy's weakest points. Once per turn, when you make an attack roll, you can choose to increase the number on the d20 roll by your proficiency bonus, potentially turning a miss into a hit. If this would cause the die roll to be 20 or higher, the attack is considered a critical hit.