Rival Schools: United by Fate, known in Japan as Private Justice Academy: Legion of Heroes, is a 1997 3D fighting game produced by Capcom originally released as an arcade game on Sony ZN-2 hardware. Rival Schools revolves around tag team battles between groups of students from various schools in a Japanese city, and uses a comical and humorous style. Sakura Kasugano from Capcom's Street Fighter series also appears as a character in the game.

An updated and expanded two-disc version of the game was ported to the PlayStation in 1998 with new minigames and a new game mode called Nekketsu Seisyun Nikki, featuring visual novel content (this game mode was removed from the NA and PAL versions of the game). A further enhanced Japan-exclusive version of the game called Private Justice Academy: Nekketsu Seisyun Nikki 2 was released next on the PlayStation, featuring an improved version of the aforementioned game mode, as well as 2 new characters. A proper sequel called Burn! Justice Academy, known internationally as Project Justice or Project Justice: Rival Schools 2, was released as an arcade game in 2000 and shortly afterwards ported to the Dreamcast.

The main fighting game is best described as a polygonal Marvel vs. Capcom game, with some notable differences. Control wise, the game imitates Star Gladiator's four button setup (two punches and two kicks, like the SNK game format).

A player chooses a team of two characters, and fights against another two character team. The actual fights, however, are one-on-one fights, with the partner only participating by being called in when a player has enough 'vigor' for a Team Up attack, done by pressing a punch and kick button of the same pressure. The Team Ups can be either offensive or defensive in nature. After the end of a round, a player (win or lose) can fight the next round with the partner from the previous round, or keep their main character in play. The 'vigor' meter (essentially a super meter) can go up to 9 levels, with Team Ups costing two levels and super moves from a single person costing one level of vigor.

Much like the Marvel vs. Capcom games, launchers can be done that allow air combos to be performed, with all characters having universal low and high launchers.

The game also has a few defensive techniques.

Rival Schools takes place in the fictional Aoharu City, where several local schools are the victims of unknown attacks and kidnappings of students and staff. The various characters in the game set out to find who is responsible for the attacks on their school, with the cut-scenes and fights portraying their interactions with the other schools and among themselves. Eventually, the story reveals that an elite school in the city, Justice High, is responsible for the attacks. The player's team eventually faces off against Raizo Imawano, the principal of the school, and first boss of the game. If certain requirements are met during the fight against Raizo, the story would continue as the player would then head into a true final boss fight against Hyo Imawano, Raizo's nephew and the true mastermind behind the events of the game.

The structure of the single player game of Rival Schools varied depending on how characters were selected. If two characters from the same school were selected (with a few exceptions), single-player would play in a progressing story with fights predetermined beforehand and each fight preceding and ending with short 2D cut-scenes to explain the story. If two characters from different schools were chosen, the single-player mode would instead play similar to other fighting games, with the player's chosen team fighting against random teams of opponents before facing the boss. In the arcade version, character selection is initially limited to selecting two characters from the same school and free selection of any character is accessed through time; the PlayStation version, which includes all characters unlocked by default, has no such restrictions.