Garry's Mod Special Tactics Sector is an arena fight simulator with up to four teams that battle against each other. Each team is given four Boxes that represent monsters that will fight for them in an arena during each round. You must win rounds to score Research Points for your team, which are used to upgrade or 'randomize' your boxes so that they have different Mob Types, or higher Strength. There are also special mini games every 2 rounds where players on each team must compete in various activities to earn Research Points to upgrade or randomize your Boxes.