Gladius

On a critical hit, the weapon adds a weapon damage die of the listed size. Roll this after doubling the weapon's damage. This increases to two dice if the weapon has a greater striking rune and three dice if the weapon has a major striking rune. For instance, a rapier with a greater striking rune deals 2d8 extra piercing damage on a critical hit. An ability that changes the size of the weapon's normal damage dice doesn't change the size of its deadly die.

A versatile weapon can be used to deal a different type of damage than that listed in the Damage entry. This trait indicates the alternate damage type. For instance, a piercing weapon that is versatile S can be used to deal piercing or slashing damage. You choose the damage type each time you make an attack.