Weapon

Common

Versatile. This weapon can be used with one or two hands. A damage value in parentheses appears with the property - this is the damage when the weapon is used with two hands to make a melee attack.
Hammer. When you attack a creature with a hammer, you gain a bonus to your damage roll equal to your prof. bonus if the target is Prone, Petrified or wearing metal armor. When you attack an object made of stone, glass, or other similar material with a hammer, your damage rolls deal maximum damage. You only gain this benefit if you are proficient with the weapon.
Bludgeoning. On a critical hit, the target is knocked 5ft in a direction of your choice and falls Prone.

Martial Special Attacks

When you land any attack in combat you can choose to make it a Special Attack by expending one of your extra attacks. The additional bonuses below are either added immediately to the attack you just landed for extra effects OR expended before you make the attack for ONE all-in strike.
Each of these Martial Special Attacks have certain requirements and if the target needs to make a save, it's always against your Martial Save DC.

Hammer. On a hit, you can forgo 1 extra attack to force the target to make a Str Save. Failure. The target takes 1 extra die of damage from the attack and is knocked 5ft away from you.
Martial Save DC. (8 + prof. bonus + Strength or Dexterity modifier)
Cleave. On a hit, you can forgo 2 extra attacks to make a wide swing with your weapon and choose a target within your reach. You can make a melee weapon attack against that target and up to 2 targets adjacent to it that are also within your reach. Use the same attack and damage roll against all creatures.
Requires. Two-Handed Weapon
Concussive Strike. On a hit, you can forgo 1 extra attack to force the target to make a Con Save. Failure. The target becomes Stunned until the end of your next turn. Once Stunned from this Special Attack, a creature is immune to the technique for the next 24 hours.
Martial Save DC. (8 + prof. bonus + Strength or Dexterity modifier)
Stagger (Combo). On a hit, you can forgo 1 extra attack to force the target to make a Con Save. Failure. The target becomes Vulnerable to the next source of Slashing, Piercing, or Bludgeoning damage before the start of your next turn. You can only do this once per combat.
Martial Save DC. (8 + prof. bonus + Strength or Dexterity modifier)
Sunder Armor. On a hit against a creature wearing armor, you can forgo 1 extra attack to force the target to make a Con Save. Failure. The target takes 1 extra die of damage from the attack and loses 1 level of Defense for 1 minute.
Martial Save DC. (8 + prof. bonus + Strength or Dexterity modifier)