An atgeir, sometimes called a mail-piercer or hewing-spear, was a type of polearm in use in Viking Age Scandinavia and Norse colonies in the British Isles and Iceland. It is usually translated in English as halberd, but most likely closer resembled a bill or glaive during the Viking age. Another view is that the term had no association with a specific weapon but was used as an anachronism in saga literature to lend weight to accounts of special weapons.
It is not used in any Viking Age source and there are no remains from archaeology which can be identified with the term. The references from saga literature are not relevant to the Viking Age but come from Iceland of the thirteenth century and later. Arguably the most famous atgeir was Gunnar Hámundarson's, as described in Njal's Saga. According to the saga, this weapon would make a ringing sound when it was taken down in anticipation of bloodshed.
The attributes of the atgeir are good. The hit throw is 1D+4 and for using both hands. The total of hit points is therefore between 4 and 8. The weapon has a slight advantage when attacking from melee range +1 tp attack but -1 for defending. The spear can be used with both hands only, which gives a better damage score then a spear. The weapon can only be used in one distance class namely melee (M). Many maneuvers can be chosen for the atgeir and there are good options for tactics in larger groups.