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.
A few people ask me for help with mapping for Day of Defeat. I used these tutorials for the original Day of Defeat to learn. They used to be on this website...