Day Of Defeat: Source is a multiplayer class-based FPS developed by Valve. The game is a remake of Day Of Defeat which was released on GoldSrc engine.
Set in 1944, the game focuses on the European war theatre and two teams: U.S. Army and Vermacht. Each team has 6 player classes: Rifleman, Assault, Support, Machinegunner, and Rocket.
DoD: Source features two game modes: territorial control and detonation. In territorial control, players fight over several strategic points on the map. In detonation, however, the objective is to detonate two bombs on every checkpoint of the opposing team.
The game features 8 official maps, but there are a lot of custom maps designed by the community members.
Day Of Defeat: Source served as a testing ground for Valve as it was the first Source-based game that featured in-engine High Dynamic Range. Several post-processing effects were added by Valve after the release of the game in order to make it look more like a 1940s era movie. The effects include film grain, color correction and depth of field.