Originally Posted by Lawdog
The most important rule, particularly for a first game is bring your sense of humour and have fun. People will understand you are a noob and hopefully cut you some slack.
With that said however. First impressions matter.
It's OK to be a bit ignorant and ask questions the first few games until you get the hang of it but make an attempt to learn and listen.
The first rule though is FUN (next to safety of course). Whether it's at a milsim game or a quick half hour scrim people go to play have fun and relieve the stress of work.