DnD Fencing Rules

These rules are an extension of current mechanics and can be used in ongoing campaigns with current character builds.
Rules: At the beginning of the turn players choose a stance. They cannot switch stance, even if they have additional attacks.
The player makes an attack role with the normal modifiers. The result is compared to target AC, and if the result equals or exceeds target AC, then the attack hits. To find damage dealt, take the result of the attack roll minus AC, and compare to the attack table for the chosen stance. The result will correspond to an attack, which has a description and a given damage. Any damage modifiers are added to damage in the normal way.
Stances will also give a modifier to AC, detailed on the damage table. This modifier applies until the player chooses another stance.
Stances will be either low damage, high AC, high damage, negative AC, or a utility stance.
Critical hits can happen in the normal way, and the damage for these attacks is given in the damage table. If using the utility stance, a crit will allow the player to perform an action instead of inflicting critical damage.