Mortal Kombat X is the tenth main game in the one-on-one fighting series and a sequel to the 2011 title Mortal Kombat, which was a complete reboot of the series. The plot is set about 20 years after the events of the previous game where the ending revealed that Shinnok used the void after Shao Kahn's death to attack Earthrealm with his army of Netherrealm forces. Several characters work together to steal Shinnok's amulet and imprison him inside, but eventually Mileena hatches a plan to release Shinnok by bringing the amulet to Quan Chi who escaped when Shinnok was imprisoned. The gap in years is mainly used to introduce the new characters to the cast, such as Cassie, the daughter of Johnny Cage and Sonya Blade (who married and divorced), Kotal Kahn as the new emperor of the Outworld, and Takeda, the son of Kenshi.

The game stays close to the visual style and the mechanics of the 2011 reboot. The main controls are still based on two types of punches and kicks, and blocking, to form combos with uppercuts, teleports, special moves that incorporate weapons and fatalities. The three-tiered energy from the previous title returns, making available X-Ray moves, powered up EX moves and combo breakers. As introduced in Injustice: Gods Among Us by the same developer characters can use the environment to re-position themselves or optionally use parts as weapons. Each character now has three variations with different moves and weapons. There is once again a sprinting gauge, returning from Mortal Kombat 4.

The trademark fatalities finishing moves are expanded with new types of finishers. Multiplayer games have quitalities where a character is immediately killed when a player leaves an online game prematurely and faction kills that are finishers tied to one of the game's five factions. Brutality finishing moves return from Ultimate Mortal Kombat 3, as powerful versions of moves that can be used at certain moments to link a combo into a finisher right away.

The recurring cast includes Ermac, Jax, Johnny Cage, Kano, Kenshi, Kitana, Kung Lao, Liu Kang, Mileena, Quan Chi, Raiden, Reptile, Scorpion, Shinnok, Sonya Blade and Sub-Zero. New playable characters are Cassie Cage, D'Vorah, Erron Black, Ferra/Torr, Jacqui Briggs, Kotal Kahn, Kung Jin and Takeda. There are 24 characters in total. Additional ones such as Goro, Jason Voorhees, Predator, Tanya and Tremor are either offered as DLC, appear as guest characters, or both. Baraka, Rain and Sindel appear in the story mode, but are not playable.

Next to the main Story mode there is King of the Hill, ranked matches, Survivor and Test Your Luck where fights have random round parameters. The Towers as challenges return, but now with play conditions that change constantly in the Living Towers. The online game has a persistent game mode called Faction Wars where players choose one of five factions (Black Dragon, the Brotherhood of Shadow, the Lin Kuei, Special Forces, and White Lotus) to fight in constant, cross-platform competitions to become the ruling faction. Competing in the Faction Wars is rewarded with a personal and faction-based leveling system, a currency, and the aforementioned faction kills. More outrageous types of fights such as one-versus-two or very difficult boss fights do not return from the previous game. Koins are the main currency in the game. They can be used to acquire secondary fatalities, brutalities, concept art, character skins and more. These are bought in the first-person dungeon crawling Krypt mode, returning from the previous game.