Piercer Feat

You have achieved a penetrating precision in combat, granting you the following benefits:

Prerequisite: None

• Increase your Strength or Dexterity by 1, to a maximum of 20.
• Once per turn, when you hit a creature with an attack that deals piercing damage, you can reroll one of the attack's damage dice, and you must use the new roll.
• When you score a critical hit that deals piercing damage to a creature, you can roll one additional damage die when determining the extra piercing damage the target takes.

Source: TCE, page 80