Team Fortress 2 is a team-based first-person shooter multiplayer video game developed by Valve Corporation. In Team Fortress 2, players join one of two teams comprising nine character classes, battling in a variety of game modes including capture the flag and king of the hill. Like its predecessors, Team Fortress 2 is focused around two opposing teams, Reliable Excavation & Demolition (RED) and Builders League United (BLU) competing for a combat-based principal objective. Players can choose to play as one of nine character classes in these teams, each with his own unique strengths, weaknesses, and weapons. Although the abilities of a number of classes have changed from earlier Team Fortress incarnations, the basic elements of each class have remained, that being one primary weapon, one secondary weapon, and one melee weapon.