Raid

Raid is a multiplayer gamemode added in the 16.2.0 update. 4 players must complete certain objectives to reach to the goal while surviving against hordes of enemies.

Strategy
If you have 4 friends (as randoms cannot be trusted normally), split into 4 roles: Sometimes you just need luck in order to win. Also communicate with your team would help more than this alone. If you have discord (or group voice chat apps), you can use them to your advantage.
 * The Main DPS. This person should be the main damage output, mainly he/she will deal with powerful bosses and swarms of enemies. Good weapon for them is Champion Peacemaker, Automatic Peacemaker or other high DPS and ammo primaries.
 * Second DPS. Backup if the main DPS dies/distracted by smaller targets. This DPS dishes out extra DPS from backup, primary and special weapons. Thunderer/Exterminator, Laser Bouncer/Reflector and Black Mamba are good weapons to use for this player in order to kill small bosses (such as chainsaw doctor and infected truck driver).
 * The Anti-Swarm. This person should be using splash damage to help the DPS when they are attacked with small, powerful threats, such as zombie dogs. The good weapons are champion solar cannon, destruction system or even the shadow spell.
 * The Support. This person should prioritise on doing objectives and supporting the team all the time. Good weapons would be a fast melee and a good sniper such as dark force saber and comet.

Monsters

 * Army Crawler (however not crawling)
 * Chainsaw Doctor
 * Infected Doctor
 * Infected Truck Driver
 * Neon Skeleton
 * Poisonous Plant
 * Raven
 * Red Slime
 * Spider
 * Spider Boss
 * Tortured Prisoner (as policeman)
 * Venom Nurse
 * Venom Spitter
 * Zombie
 * Zombie Cat
 * Zombie Dog
 * Zombie Head
 * Zombie Policeman

Bosses

 * Triple Headed Zombie
 * Monster from the deep

Goals

 * ”Defeat the Boss!”
 * ”Pick up the key”
 * ”Enter the location”
 * “Destroy all hives”
 * “Collect all virus samples”

Trivia

 * It is similar to Garden Ops for Plants vs Zombies :Garden Warfare. For example, ”Destroy all hives” are basically “Destroy all tombstones”. However, the difference here is that you do not have to defend a location in order to win in raid.