Rainbow Six is a tactical shooter video game and the first in the Rainbow Six series. It was developed and published in 1998 by Red Storm Entertainment for Microsoft Windows. It has been ported to Mac OS, Nintendo 64, PlayStation, Game Boy Color and Dreamcast. Based on the novel of the same name by Tom Clancy, the game follows Rainbow, a newly formed international anti-terrorist organization, and the conspiracy they uncover as they handle several seemingly random terrorist attacks. In single-player mode, players progress through a series of scenarios by playing missions in a campaign. Each mission begins with a briefing phase that allows the player to select equipment, coordinate attacks, and advance the plot. During each mission, the player directly controls a team member and can take control of any living agent. However, losses cannot be used in future missions unless the mission is reset. In multiplayer mode, two teams of players compete against each other to complete objectives, depending on the game mode.