General Feat (Prerequisite: Level 6+ in classes with Weapon Mastery or Martial Arts features)

You gain the following benefits.

Ability Score Increase. Increase your Strength or Dexterity score by 1, to a maximum of 20.

Mastery Stance. As a bonus action, you can focus your martial abilities to activate a stance which allows you to increase the damage of weapon attacks made as part of the attack action.  The damage dice of your weapons or unarmed strikes increase by an amount based on your proficiency bonus. If you have a shield equipped, the armor bonus from the shield is a minimum of +3. While in this stance you cannot cast spells or concentrate on spells and other effects which require concentration. The stance lasts until you end it as a free action, begin a short or long rest, or become Unconscious, Petrified, or Dead (or any other condition that makes you unaware of your surroundings). The extra dice is additional Weapon damage dice and is included in other abilities that are based on the Weapon dice (Savage attacker, Critical hits, Great Weapon fighting, Full Attack, etc).

Proficiency bonus +3 results in +1d4, +4 is +1d6, +5 is +1d8, and +6 is +1d10 in additional damage dice per attack made as part of an attack action (average damage is slightly below the Proficiency bonus).