Fighting System

Character Creation:
Players create their fighter characters, choosing their race, class, abilities, and stats. The race could be a human, elf, dwarf, or any other fantasy race, and the class could be fighter, rogue, monk, etc. The abilities could include things like grappling, striking, kicking, submissions, etc., and the stats could include strength, dexterity, constitution, etc.

Initiative:
At the beginning of each round, each player rolls a d20 to determine their initiative order. The player with the highest roll goes first.

Attacks:
To attack, a player rolls a d20 and adds their relevant ability and stat modifiers. If the roll beats the opponent's armor class (AC), the attack hits and the player rolls damage dice (depending on the weapon used or the type of attack made) to determine the damage dealt to the opponent's health points (HP).

Defense:
To defend against an attack, a player rolls a d20 and adds their relevant ability and stat modifiers. If the roll beats the opponent's attack roll, the defense is successful and the player takes no damage. If the roll is lower, the player takes damage according to the opponent's damage dice.

Grappling:
To grapple, a player must first make a successful attack against their opponent. They then roll a d20 and add their grappling ability and stat modifiers. If the roll beats the opponent's defense roll, the player successfully grapples their opponent, and the opponent must break free on their next turn by rolling a contested roll of d20 plus their relevant ability and stat modifiers against the player's grappling roll. If the opponent fails to break free, they are immobilized and unable to attack or defend until they break free.

Submissions:
To attempt a submission, a player must first successfully grapple their opponent. They then roll a d20 and add their submission ability and stat modifiers. If the roll beats the opponent's defense roll, the player successfully applies the submission hold, and the opponent must roll a contested roll of d20 plus their relevant ability and stat modifiers against the player's submission roll on their next turn. If the opponent fails to break free, they must tap out and forfeit the match.

Knockouts:
If a player reduces their opponent's HP to 0 or below, the opponent is knocked out, and the player wins the match.

Points:
If the match lasts for a set number of rounds (e.g., 3, 5, or more), points can be awarded for successful attacks, defenses, grappling, submissions, and knockdowns. At the end of the match, the player with the most points wins.

Unique moves:

Players will have the opportunity at times to learn or create signature attacks.  These attacks may only be used once a fight but if successful can result in a KO.

It's up to the players to decide on the specifics, such as the exact number of dice and modifiers to use, the range of attacks and defenses available, the point system, and any other rules and variations they want to include.