A lucern hammer is a heavy medieval polearm. It consists of a pole of up to 10 feet in length, with a large hammerhead at the end. Opposite the hammer head is a large spike (where the claw would be on a normal hammer). The end of the pole will often be mounted with yet another spike, allowing this weapon to be used in several different attack modes.

The lucern hammer is mostly a defensive weapon, properly used in a formation with 10 or more men wielding identical hammers, although a skilled warrior can use this to smash men who are attacking the rank in front of him. These hammers are very heavy, often being made totally out of steel, including the pole itself. They often feature some highly decorative metalwork, and are one of the more expensive polearms in most Fantasy Role-Playing games.