Captain Price is back in the brand new Modern Warfare story trailer. Modern Warfare's single-player campaign will focus on realism as well as featuring tactically-based moral choices. The player is evaluated and assigned a score at the end of each level; players will have to quickly ascertain whether NPCs are a threat or not, such as a civilian woman who is believed to be reaching for a gun, but then simply grabs her baby from a crib. Character dialogue will also vary depending on choices the player makes in-game.

Tactical decisions are also included, such as the player using a sniper rifle in a large environment to approach objectives in a non-linear order, and choosing to shoot out lights in favor of using night-vision goggles during breaching and clearing.

Modern Warfare will be the first game in the series since 2013's Call of Duty: Ghosts not to feature a Zombies mode,instead featuring the cooperative "Spec Ops" mode previously present in Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3, instead it has been blended into the main story mode and co-op modes.The game's multiplayer has been revised for more tactical gameplay, including a focus on map exploration and door breaching. There is a new "Realism" mode that removes the HUD. The mini-map has been replaced by a compass.

Multiplayer also features the return of Killstreaks (rewards based on kills), with more recent Call of Duty titles having used Scorestreaks (rewards based on score) instead. The online modes allow for a larger range of players within a map than previous installments, with a new mode called "Ground War" featuring over 100 players. A second new mode called "Gunfight", tasks two teams of two players against each other in small matches lasting forty seconds per round. The game also boasts of a large weapon inventory and customization allowing for up to 60 different options for most weapons.