This achievement and the other 'Tours of Duty' achievements will take you some time and dedication on the multiplayer. You will have to win 3 MP game modes:
Siege & Decoy
Choose one game mode until you have won on each map. I suggest making a checklist of the maps name and what game modes you have won on them.
Note: You can win the same game mode 3 times for each map, it doesn't have to be 3 different ones.
**Some say this can be done in quick matches. A win does not count if you join a session in progress or if the host leaves. If anyone could confirm this, please PM or post in thread**