Bosses are strong enemies found at the end of every floor in The Gungeon. Defeating a boss allows the player to advance to the next main floor.
Upon being killed, bosses drop a weapon or item of random quality, several Hegemony Credits, and one to three pickups such as hearts, ammo, or keys.
Bosses will always drop a gun if the player has not yet picked up a gun on the current floor.
This can seemingly be worked around by throwing an empty gun using the Fire button and picking it back up; which could be useful if you want "a chance to get an item" instead of "guaranteed gun reward", but are out of keys to open any chests in the floor, and out of money to purchase any guns in the shops.
Dropping and then picking up guns with the "Drop Gun" button instead doesn't seem to work for this purpose, instead probably still guaranteeing a gun if you haven't gotten an actual new gun in the floor in any other way. (confirmation & testing needed)
If a boss from one of the five main floors is defeated without getting hit, they will drop a Master Round as well. Clearing a boss without getting hit will also cause it to drop doubled Hegemony Credits.
Every boss has a DPS (damage per second) cap as a way of stopping players from dealing high amounts of damage over a short time, so guns with high fire rate or high damage can't destroy bosses in seconds.
The DPS cap is applied across a 3-second window.
The most damage a single shot can deal is equal to triple the floor's DPS cap.
In Boss Rush, bosses have no damage per second cap.
