English Bill (5e Equipment)
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Martial Melee Weapons
Billhooks have the potential to dismount cavalry. When you make a successful slashing attack against mounted opponents, they must make a Strength saving throw. The DC for this saving throw equals 8 + your Strength modifier + your proficiency bonus. On a failed save, the target is dismounted from their mount.
A standard Billhook.
Billhooks evolved from the bill, a tool used for cutting branches off trees. As with many other tools, the poor would take them into battle, and thus over time they evolved into a weapon. Various countries had different styles, and this is the English version. They were actually very popular weapons because they were pretty effective, and they were essentially the poor man's halberd. Another, benefit of using the billhook was the potential to dismount cavalry. If the strike of the weapon didn't kill the rider, it could potentially lock into the different pieces of their armor and bring them down. A soldier with a billhook was called a "billman".