1. Establish Boundaries

   Before any game begins, be sure to talk a walk around the field and clearly indicate the boundaries to everyone who will play. Make sure that your field is not too big or too small. A field a hundred yards long and fifty yards wide is great for 3 on 3, but if you have sixteen people, you need more room. Establish starting bases on opposite sides of the field and, if possible, make it so they are not in view of each other. Note that if you are playing on a speedball course with no trees or brush, this won't be possible.
    

2. Mark Dead Zone

   Make sure everyone knows the location of the dead zone (or staging area) and knows to not shoot in or near it. The dead zone is an area that is off of the field where people go after they are eliminated. Typically it's also where extra paintball gear and paint is left between games. The dead zone should ideally be far enough off the field that eliminated players can remove their masks to clean them without risk of being hit by players still on the field.
    

3. Game Objective

   Make sure everyone knows what the goal of the game is. Are you playing a simple elimination game? How about capture the flag or center flag? Broadcast clearly any special rules or objectives.
    

4. Time

   Establish a time limit for the game. Nobody likes to play in a game that lasts forever with neither team moving. There are two primary ways of timing a game: start timing from the start or else start timing from when the first person gets out. Remember that long games are not fun for people that get out at right at the start, so keep them short and sweet.
    

5. Teams

   Divide up into fair teams. If some people are new to the sport and others are more experienced, divide them up between the teams. In general, try to keep the number of people on each team about equal. If there are just a few people playing it's not too hard to remember who's on your team, but if there are larger groups of people, tie some colored tape or cloth around your arms or guns to identify different teams.
    

6. Start

   The game begins when both teams are set at their respective bases. One team calls out that they are ready, the other team responds that they are also ready, and then the first team calls "Game On" and the game begins.
    

7. Hits

   A player is hit if a paintball leaves a solid, nickel-sized mark anywhere on the player's body or equipment. Some variations of paintball don't count gun hits or require multiple hits on the arms or legs. Most professional fields and tournaments, though, count any hit on a person or their equipment. Splatter often occurs when a paintball does not break on a person but on a nearby surface and then paint bounces onto the player, but this does not count as a hit unless it forms a solid mark on the player.
    

8. Paint Checks

   If you think you might have been hit but can't tell for sure (such as if your back was hit, but you can't tell if the ball broke), you can call a paint check. Shout "Paint Check" and the closest player to you (on your team or the other team) will come and check you. If you are hit, you will then exit the field, otherwise everyone returns to their previous position and the game is resumed when the player who initiated the paint check shouts "Game On!".
    

9. Walking Off the Field

   When a player is hit, they must then raise their gun over their head, shout that they are hit, and then quickly leave the field to the dead area. Be sure to keep your gun over your head and to shout that you are hit whenever you come across new players.
    

10. Victory

    When one team has completed the necessary objectives, all players still on the field should be notified. Do not remove masks until barrel plugs or barrel covers have been placed on all loaded guns.

    After you have played one game, try out a new game type and repeat the steps from the beginning.

Follow all safety rules.

Briefly, the basics are:

• Wear Masks at All Times

• Do Not Drink and Play

• No Blind Firing

• Allow Surrenders

• Shoot less than 280 FPS

• Use Barrel Plugs

• Use Common Sense

Do not remove masks until barrel plugs or barrel covers have been placed on all loaded guns.
 

Typically when you play on an established field, they will provide you with equipment as part of your entrance fee.  You can buy and bring your own gun, but expect to buy your paint from the field operator.