Polearm Master: Bonus Attack is a Passive Feature provided by the Polearm Master Feat. When attacking with a polearm, you can also attack with a 
Bonus action.
Description
When attacking with a 
Glaive, 
Halberd, 
Quarterstaff, or 
Spear, you can use a Bonus Action to attack with the butt of your weapon.
How to learn
Granted by feats: Polearm Master
Notes
- This attack uses the same ability modifier as the primary attack. The weapon's damage die for this attack is a d4, and it deals bludgeoning damage.
- (NOTE: Currently bugged and does not add bonus damage from sources other than the ability modifier.)