An attached weapon must be combined with another piece of gear to be used. The trait lists what type of item the weapon must be attached to. You must be wielding or wearing the item the weapon is attached to in order to attack with it. For example, shield spikes are attached to a shield, allowing you to attack with the spikes instead of a shield bash, but only if you're wielding the shield. An attached weapon is usually bolted onto or built into the item it's attached to, and typically an item can have only one weapon attached to it. An attached weapon can be affixed to an item with 10 minutes of work and a successful DC 10 Crafting check; this includes the time needed to remove the weapon from a previous item, if necessary. If an item is destroyed, its attached weapon can usually be salvaged.

These weapons smash as much as puncture. When determining a creature's resistance or immunity to damage from this weapon, use the weaker of the target's resistance or immunity to piercing or to bludgeoning. For instance, if the creature were immune to piercing and had no resistance or immunity to bludgeoning damage, it would take full damage from a concussive weapon. Resistance or immunity to all physical damage, or all damage, applies as normal.

The fatal trait includes a die size. On a critical hit, the weapon’s damage die increases to that die size instead of the normal die size, and the weapon adds one additional damage die of the listed size.

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.