Batman: Arkham Knight is an action-adventure and the fourth main game in the Batman: Arkham series based around the DC Comics superhero Batman. It marks the return of the original developer of the first two games. It is set one year after the events of the second game Batman: Arkham City. It starts when Scarecrow forces an evacuation of Gotham City by threatening to release a fear toxin. Many familiar characters and foes are present. The title refers to a new villain called Arkham Knight who backs Scarecrow. He wears a militaristic Batsuit and an Arkham symbol on his chest.

The game is set in an open world environment for Arkham City with main missions, side missions and the Riddler trophies that can be pursued freely. Familiar game elements return, such as the many melee combat sections, the use of gadgets and stealth abilities, and detective skills to examine clues in the environment and solve puzzles. Gadgets are used both during combat and while exploring. They include batarangs (now also used as a way to explore the environment), the batclaw, a disruptor, an electrical charge gun, explosive gel, freeze blast, grapnel gun, a line-launcher, a remote hacking device, smoke pellets, a voice synthesizer etc. Many of these return from previous games. Exploration is largely done using long flights with the cape.

An entirely new game element is the introduction of the batmobile as a playable vehicle for both exploration and combat. While on foot it can be summoned right away and Batman is able to eject to go into flight without interruption. The car is bulletproof, can smash through obstacles and is equipped with weapons. There are two modes to control the vehicle: Battle or Pursuit. Pursuit is used mostly for transportation and driving challenges. Battle provides tank-like controls for the car, with 360-degree range of movement, strafing and a large weapons arsenal. Next to the regular gameplay there are many sequences where the batmobile is used. The car can be controlled remotely and various upgrades such as an EMP gun can be equipped.

The combat retains the familiar combo and counter system. Enemy medics are new. They are able to shield certain enemies or revive unconscious ones. Fights are rewarded with experience points that are used to unlock new moves, health upgrades and new abilities for gadgets. Batman sometimes fights along allies (Catwoman, Nightwing, Robin) and the game introduces a Dual Play system where seamlessly switching during combat provides access to double takedowns.