The multiple attack penalty you take with this weapon on the second attack on your turn is –4 instead of –5, and –8 instead of –10 on the third and subsequent attacks in the turn.

When you hit a flat-footed creature, this weapon deals 1 precision damage in addition to its normal damage. The precision damage increases to 2 if the weapon is a +3 weapon.

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.

You can use your Dexterity modifier instead of your Strength modifier on attack rolls using this melee weapon. You still use your Strength modifier when calculating damage.

You can use this weapon to Grapple with the Athletics skill even if you don't have a free hand. This uses the weapon's reach (if different from your own) and adds the weapon's item bonus to attack rolls as an item bonus to the Athletics check. If you critically fail a check to Grapple using the weapon, you can drop the weapon to take the effects of a failure instead of a critical failure.

A creature with this trait is a member of the kobold ancestry. Kobolds are reptilian humanoids who are usually Small and typically have darkvision. An ability with this trait can be used or selected only by kobolds.

Something of uncommon rarity requires special training or comes from a particular culture or part of the world. Some character choices give access to uncommon options, and the GM can choose to allow access for anyone. Less is known about uncommon creatures than common creatures. They typically can't be summoned. The DC of Recall Knowledge checks related to these creature is increased by 2.