In Team Fortress Classic, a player can choose to play as one of nine standard classes. Each class comes equipped with at least one weapon unique to that class, and often a secondary weapon which may be common across multiple classes (typically a shotgun or nailgun). Additionally, each class gets a melee weapon (all classes but the Medic, Spy and Engineer wield a crowbar, a homage to Valve's game Half-Life). Finally, each player carries grenades; the effects of grenades vary, depending on the player's class.

In Team Fortress Classic, a server can hold up to 32 players simultaneously, and matches can be played in a number of game modes, each featuring different objectives..