I'm new to Offline missions.

[ACE]

I downloaded the Attrition mission that ranger put up to my desktop.  How do I play it in the offline missions.

[USRanger]

Load the terrain offline, select Practice Missions on your clipboard, choose your flight, play away.  The .res file for the mission goes in your MISSRES folder if you didn't know yet.  Ya gotta put that in there first.