Class Warfare is a Team Fortress 2 server plugin created by Flynn99 in which every round, each team is forced to play as a single class.
Every round, each team is restricted to a specific class. For instance, there could be a team of Pyros against a team of Medics. This creates an interesting dynamic as it could pit two classes that are natural enemies against each other. At the start of every round the class restrictions placed on both teams is displayed on screen. This means players always know what they’re up against. If the class restrictions aren’t displayed this indicates that there is a free round where every player can play as whatever class they wish to play. Aside from the class restrictions, everything else is exactly the same as a regular game of Team Fortress 2.