Marvel vs. Capcom: Clash of Super Heroes is a 2D tag-team fighting game developed and released by Capcom for the arcades (running their CPS-2 hardware) on January 23, 1998.
The third installment of the Marvel vs. Capcom crossover series (and sequel to Marvel Super Heroes vs. Street Fighter), the game adds fighters from various Capcom games (unlike the previous games, which were from the Street Fighter Alpha series) to fight alongside Marvel's superheroes. It also adds dedicated characters for the "assist attack" (known as "partners") and a special combination attack (known as the "Duo Team Attack", which temporarily allows the player to control both of their fighters simultaneously).
The game was ported to the Dreamcast on September 30, 1999, adding a new game mode (called "Cross Fever") that allows four-player simultaneous gameplay. It was later ported to the PlayStation on January 31, 2000, restricting the tag-team mechanic to the "Cross Over" mode (where each player's secondary fighter is the same as the opposing player's primary fighter). Like the PS1 ports of the series's previous games, normal gameplay uses traditional round-based 1v1 fights (where players can choose between a "partner" or another fighter as their assist character).
The original version was later digitally re-released in a bundle (with Marvel Super Heroes) for the Xbox 360 (via Xbox Live Arcade) and PlayStation 3 (via PlayStation Network) in September 25, 2012 as Marvel vs. Capcom Origins, including online multiplayer, graphical filters and 3D viewing angles, and a challenge system (where players can unlock bonus content by completing challenges in the game).
Marvel vs. Capcom: Clash of Super Heroes was distinguishable from the rest in the series due to the ability to call upon the help from "assist" characters, as well as the ability to perform a special attack where both of the characters would be in the field at the same time. The game plays quicker than other 2D fighting games at the time. Play focuses heavily on quick reactions, smart team management, and both solo and team super moves.
In addition, this game introduced the Duo Team Attack. In the Duo Team Attack, both characters on the team could be controlled simultaneously and had an unlimited use of super moves during the time. In the PlayStation version, the Duo Team Attack worked where the assist character could be summoned repeatedly during this time. The game starts off and the player gets to choose two characters. Then, the fighting starts, with randomly selected pairs of other characters gradually increasing in difficulty until the final boss, Onslaught.
The game includes 15 playable characters at the start, one secret fighter, five secret variations, and one unplayable final boss (with two forms).
It is the first entry in the series to include Capcom characters outside of the Street Fighter series and replaces most of their part of the previous game's roster with them (leaving only Ryu, Chun-Li, and Zangief). It is also the first game in the series to include War Machine (based on the sprites used for Iron Man in Marvel Super Heroes).