Knowing some basic paintball rules will make your first game much more enjoyable. When you know rules, you won't show up dressed inappropriately or with wrong equipment and marker. At least, knowing rules can save you some embarrassment; at most, it can save you from finding out you're not allowed to play.1. Eliminations and Markings
According to American Paintball League's rules for tournament paintball, "A player is eliminated from game when he is marked anywhere on his body, clothing or equipment with a quarter-sized or larger splat caused by a direct hit from a single paintball." The size of splat that indicates elimination may vary from tournament to tournament and field to field. Tournaments may also have rules for other kinds of marks, including size of combined splats.
Other considerations will be: who to eliminate if two players are hit at same time (usually both), what a player should do if they think they're hit but can't see mark, how persistent a player is in seeking verification from a referee, etc.
2. Vandalism
Shooting at anything outside shooting range and playing field will be considered vandalism. Cars, spectators, lights, speakers, buildings, birds, and critters are OFF LIMITS!
3. Gun Safety
You must use a barrel blocking device except when in playing field or on shooting/chronograph range. A barrel blocking device could be a barrel plug or sock. A plug goes into barrel, whereas a sock fits over barrel.
A chronograph is a device that uses sensors to measure velocity (speed) of a paintball leaving barrel. You will be required to check your gun's speed at any commercial paintball field. Paintball guns are capped at 300 feet per second, but some fields will require a velocity of 280 FPS or less (e.g., for playing indoors or at night).
Your marker will be chronographed before every game. Tournament players may be required to have their gun chronographed during and after game as well. Penalties are applied for tournament players found with "hot guns" unless player asks for a chronograph.
Fully automatic guns and guns with autoresponse triggers are not allowed on commercial paintball fields or in tournaments.
4. Insurance and Waiver Forms
You will be required to sign a waiver to relieve paintball field or organization of any liability if you get hurt, or your equipment is damaged or stolen. If you are concerned about personal injury insurance or theft insurance, you should check with your insurance agent. An example of a waiver can be found here: http://www.diehardpaintball.com/cgi-bin/waiver.asp.
5. Surrender
Many fields will expect you to follow their recommendations for surrender. In other words, if you are 5, 10, 15 or even 20 feet from an opposing player, you should ask them to surrender. If they fire at you instead of surrendering, you are usually free to return fire.
6. Structures
Climbing on bunkers, structures, buildings, logs and trees is not usually allowed in tournaments or on commercial paintball fields. Altering structures, trenches or bunkers is also not allowed. However, both these things may actually be encouraged in scenario games.
7. Referees and Judges
The decisions of referees or judges (tournaments) are final. Arguing with a referee will get you eliminated from game. If you need to dispute a point with a referee, wait until after game.