Piercing : Piercing damage is any that inflicts injuries primarily with a stabbing attack. Weapons that can deal piercing damage include spears, some swords and knives, bows, and firearms.
Bludgeoning : Bludgeoning damage comes from attacks that deal primarily blunt-force trauma. This could include a club, mace, collision with the ground, or even the shockwave of an explosion. As most bludgeoning weapons rely on a large mass to deal damage, bludgeoning weapons made out of lighter materials (such as aluminum, titanium, and mithril) deal one die smaller damage.
Slashing : Slashing weapons use a sharp edge to deal cutting damage. Weapons that deal slashing damage include most blades, axes, and shrapnel from explosions.