Warner Bros. Interactive Entertainment chose to bring a single game to E3 2021 and that was Back 4 Blood. Players were treated to a first look at the game’s PvP mode known as Swarm. The details included the playable Ridden and the strategies the Cleaners will need to deploy if they’re going to outlast the other team.Swarm is a 4v4 mode where the two teams battle to see whose Cleaners can last the longest against the Ridden. Teams will swap sides for each round, the winner being the team of Cleaners that lasts the longest. Each match is the best of three rounds.Cleaners will have a range of weapons at their disposal, including handguns, shotguns, LMGs, SMGs, and sniper rifles. The Cleaners need to scavenge for supplies, such as finding stocks, silencers, scopes, and sights for their weapons, fuel tanks, first aid kits, ammo, and other useful items. Finally, they need to pick a good spot on the map to fortify and hold out, and then last as long as they can against the other team who will be controlling the Ridden. As the round progresses, the Swarm moves ever closer. This increases the size of the Ridden attacks and shrinks the playable space for the Cleaners. It may even force them out of their chosen spot.The Ridden need to kill the cleaners as fast as they can. This is done by choosing the right Ridden to counter the other team’s strategy, coordinating attacks with fellow players and AI. The Ridden gain points as they battle against the Cleaners. These can be spent on team-wide upgrades known as Mutations. The Mutations can be used to add effects to the Ridden’s abilities, or they can be used the buff the number, size and strength of the AI waves. These Mutations will persist between rounds. At the start of each round there is a choice of nine playable Ridden from three distinct groups, although each has their own ability:Group 1: Reeker, Retch and ExploderReeker has a fast hitting melee attack like Left 4 Dead‘s TankRetch has a vomit blast like the BoomerExploder will explode upon death.Group 2: Stinger, Hocker and StalkerStinger has a light ranged attack like the Spitter and can cling to wallsHocker has a melee swipe and projectile phlegm that roots players to the spotStalker has a Hunter-like leaping pounce and drag attackGroup 3: Tallboy, Crusher and BruiserTallboy has an overhead smashCrusher can grab and squeeze CleanersBruiser has a frenzy melee attack and a burst smashBack 4 Blood had already made an appearance during the Summer Game Fest Kickoff Live event with a short teaser trailer. During the Xbox and Bethesda show, the game got an extended version of the trailer, giving us a closer look at the dangers the Cleaners will face.Players will be able to take the game for a spin when it’s released on PS5 and PS4 on October 12. Before then there will be an open beta starting on August 12 and running until August 16. Those who pre-order the game will get early access to the beta between August 5-9.