Bosses are battles in which multiple players can attack the same target. These battles usually last multiple days in which the players spend their stamina to attack the bosses. Killing a boss rewards the player with many pieces of awesome loot, depending on how many 'points' you earn. There are also a number of Achievements that can be earned by killing bosses.
The bosses can be accessed by tapping on the stamina icon and selecting one of the boss options; boss list or summon boss. Once in the bosses screen, the 'Yours' tab shows any bosses that you are currently taking part in. The 'Public' tab shows other players bosses which you can join. Finally, the 'Create' tab shows a list of all the bosses that you can summon.
Legend Bosses have three summoning requirements: a cell phone, a passport, and having earned at least a 2-star rating on an associated boss. Even those who attempt to join an existing Legends boss must meet the latter two requirements. The passport is consumed when joining the battle.
Most boss battles have a number of stages, with one or more foes in each stage. Each foe has a class (see below). You can choose which enemy to attack, how much stamina to spend and whether to use a normal attack or the special attack from your class. The enemy will do damage to one of the people attacking it if it survives your attack. Once an enemy is down to a certain level of health, you will have the option to execute them.
The following lieutenants have powers that specifically affect boss fights:
When you join a battle, you choose your class for that battle. Each foe you meet also has a class. If a secondary class is unlocked, entering a boss fight as the parent class earns a small amount of class XP for the secondary class. (eg, entering as an Enforcer earns a small amount of Titan class XP if unlocked). This secondary class XP may be enhanced by having Fleur seated. Certain classes do additional damage when they use their class-specific attack against certain other classes:
- Enforcers do extra damage against assassins.
- Assassins do extra damage against heavy weapons.
- Heavy Weapons do extra damage against snipers.
- Snipers do extra damage against enforcers.
There are currently 28 bosses in the game:
- Alpha in the Slums area
- The Uncorrupted in the Train Tracks area
- Bone Breakers in the Midtown area
- 'Ghost Killer' in the Meatpack area
- Victor's Demolishers in the Downtown area
- 'The Titan' in the Westside area
- 'MURDA Gang' in the SoCal area
- 'The Mastermind' in the Italy area
- De Koningen in the Amsterdam area
- Cartel Jungle Ops in the Colombia area
- Cataclysm in the Russia area
- Dragon Core in the Hong Kong area
- Knights Templar in the France area
- Death Cartel in the Mexico area
- Death Dealers in the Las Vegas area
- The 4 Deadly Assassins in the Japan area
- The Sand Corsairs in the Dubai area
4 Legend Bosses that are extremely challenging and that require certain items to summon:
- Skull Soldier can be summoned with a Skull Ring
- Skull Elite can be summoned with a Skull Watch
- Skull King can be summoned with a Skull Medallion
- Mafia Insurrection can be summoned with a Stolen Painting or a Mafia Insurrection Insignia
- Phoenix Resurrection can be summoned with a Stolen Diamond or a Phoenix Resurrection Ring
- Storm Raiders can be summoned with an Ancient Statue or a Storm Raiders GPS
1 Other Bosses that is uniquely non-legendary and requires a sat-phone acquired from other bosses.
- War Hounds can be summoned with the War Hounds Sat-Phone from Knights Templar, Cataclysm, or Dragon Core.
- Million Man Boss ran from 1-8 July 2014
- Million Man Boss: Assassin's Showdown ran from 21-28 Jan 2015
- 100px Million Man Boss: Winter Wolves ran from 19-26 Aug 2015
Finally, there are 4 Retired Bosses that are no longer part of the game:
- Red Phoenix Clan, previously a Tech Lab Boss, summonable with a Stolen Diamond until March 2015.
- The Illuminati, previously a Tech Lab Boss, summonable with a Stolen Painting until February 2015.
- The Medellin Resurrection, previously a Tech Lab Boss, summonable with an Ancient Statue until December 2014.
- 'Doomsday', previously in the Russia area until 21 July 2015.