Halberd

Halberds were a type of two-handed, martial melee weapon in the pole arm family.

Description
The business end of a halberd had three main parts: the axe-head, the back spike and the spear tip. While many pole arms had similar structure, halberds had a few distinguishing features. Their axe-heads were concave (curving inward) to nearly straight, instead of convex like most axes. They were also set at an angle to the shaft instead of being mounted perpendicular. Their back spikes were fairly short and angled slightly downward. Some had spear tips that were long and slender, while others were medium length and broader (often on ceremonial weapons). They were generally in length or longer with their spear tips.

Weaponology
Known colloquially as a "Medieval Can-opener" due to its effectiveness against plate armor, the design of the weapon, with its ability to mount slashing, piercing, or tripping/dismounting attacks mad it extremely versatile against many different opponents. However, its large size was often considered detrimental when fighting in close quarters.

2nd Edition
The halberd was a popular weapon in the Middle Ages but did not fare as well against cavalry as the pike. However, halberdiers could attack the flanks of a pike formation with great effect because the pikemen could not bring their much longer weapons to bear in close combat. The average halberd cost 10gp and weighs 15 pounds (7kg).

3rd Edition
In 3rd edition Dungeons & Dragons, this weapon is considered a reach weapon and can deal slashing or piercing damage at the attacker's option. It is also capable of making dismounting and tripping attacks against suitable opponents.

3.5 Edition
Halberds will do double damage on a successful hit when set against a charging opponent. The back hook of the halberd can be used for trip attacks. If you are tripped during your own trip attempt, you may drop the weapon to avoid being tripped. . The average halberd costs 10gp and weighs 12 pounds (5.5kg). It does piercing or slashing damage but is not considered a reach weapon.

4th Edition
In 4th edition Dungeons and Dragons, the halberd is a two-handed melee weapon with reach, belonging to both the pole arm and axe weapon categories.

Realmslore
Halberds were by far most common in "civilized" areas of Toril with few, if any barbarian type characters choosing to wield it. Though cultures in Faerûn, Kara-Tur, and Zakhara may have hadsimilarly designed weapons, they were far less common, if not considered rarer, than in the interior areas of Faerûn. Many large city-states also fielded units of halberdiers for defense.