First off I am not claiming to be correct, or to be extremely knowledgeable on the subject, but i will be updating this instructable as i learn. also i will be updating the pictures with my own
Also this is based on the uk airsoft scene but should be good for everybody...
Step 1: The basic rules of engagement
In short a sport/activity that involves 2 or more teams of players running around an arena Firing 6mm or 8mm 0.2-0.35g plastic balls at each other traveling at anywhere upto 350 feet per second for fully auto weapons. Most common arenas seem to be woodland but can also take place indoors, in an open environment or a combination of the three.
The rules are pretty much the same at all sites regarding hits, if you are hit by a BB (ballistic ball) anywhere on the body you are dead, although unlike paintball there is no immediate mark and is completely honor based. In short you get hit, you declare yourself dead this is known as calling your hits.
My best advice is listen to the marshalls for the rest.
Oh I wont say it doesn't hurt, although I do not recommend wearing so much clothing that you cannot feel your hits, it doesn't hurt that much.