Street Fighter X Tekken is a crossover of the two Japanese fighting game series Tekken and Street Fighter. It is made as a 2D Street Fighter game with the series' trademark mechanics, but incorporating licensed characters from the Tekken series.

The game uses the visual style introduced with Street Fighter IV and incorporates core moves such as Super Combos and EX Attacks. The focus is largely on tag team gameplay where players can quickly switch between characters during a fight and also alternate between characters during complex combos. These attacks are called Cross Rush, Cross Arts and Cross Assault. In the same vein victory conditions imply that the first player to have a character with zero health loses, opposed to having the entire team defeated. Most of the special attacks are performed by filling up a three-tier Cross Gauge to activate them. Street Figher characters use the classic six-button system while Tekken characters rely more on a four-button system used in that series.

This game introduces two entirely new systems. With the gem system players can select three gems for the characters, boosting the statistics attack, defense, speed, vitality, assist, and Cross Gauge. These are activated by fulfilling certain conditions during fights. Secondly, the pandora mode allows a character with less than 25 health to sacrifice himself to have the other character acquire more strength and an infinite Cross Gauge. This effect is however limited in time and if the opponent is not quickly defeated, the game is lost. Both local and online multiplayer are supported in various game modes.