Day of Defeat: Source features multiplayer, team-based gameplay set in the WWII European theatre of operations. Players choose a role and tackle goal-oriented missions based on historical operations.

 Day of Defeat: Source takes the classic gameplay of the original Day of Defeat and improves the experience with Source, the advanced engine technology Valve created for Half-Life 2. With this technology, DoD: Source offers state of the art graphics (including support for HDR lighting) in optimized versions of popular maps, plus redesigned sound and all new player, weapon, and world models.