Capture the Flag
The classic paintball war game is capture the flag. This game can be adapted to fit as many players as necessary and the instructions are easy to follow. Play capture the flag on a paintball course, or even in the woods.
Give each team a flag, or, to put a unique spin on things, allow each team to make their own flag. Reveal the flags once they are ready, so that each team knows what to search for. Players who are shot must leave the game, and the first team to capture the enemy's flag wins. You can play this game with multiple teams if you have a large group. Capture the flag can be an all-out, week-long event for a serious group of players, or a quick, easy event for beginners.
Shoot the Captain
Shoot the captain is a game perfectly tailored for smaller groups. One player from each team is designated the captain. Identify the captains by having them wear a specific color armband. Give each team 10 minutes to come up with defensive and offensive strategies. The point of the game is to shoot the other team's captain, which is easier said than done. The team that gets the other captain first wins. You can employ a defensive strategy by hiding and protecting your captain and letting the enemy come to you. Some teams like to send their whole unit out to get the opposing captain, while leaving their own captain to fend for herself.
Prisoner of War
For the serious and more skilled paintball player, prisoner of war is a challenging war game. The goal of each team is to capture and "imprison" as many of the other team's players. You can rope off an area for prisoners, or for more advanced groups, fashion a shelter to hide the POWs. This game is the perfect all-day or multi-day game, as it gives each team the chance to come up with intricate strategies. The team that ends the game with the most prisoners wins. Make sure that each team has its designated colors to keep things clear. Don't forget the walkie talkies or cell phones if you are going to be out in the woods, so that you can convey orders and conditions to your teammates.