This Game is meant for Boy Scouts.

Make two teams.
Mark off a play area about 40 feet by 20 feet with a center line.

Strategies to not get trapped develop.
Be careful of larger scouts being too agressive.

Teams take turns raiding into the opposing team's territory in an effort to steal all the players (or knock them out of the game).
One scout is chosen to raid. He runs into the opposing team's side of the play area and tags as many scouts as he can and then returns to his side.
If he makes it back in less than 15 seconds, everyone he tagged joins his team or are out of the game.
If the opposing team stops him from returning in time, he only returns empty-handed.

The second team then gets a chance to raid.
Continue until all scouts are on one side or one team has been tagged out.
You can make a rule that a different scout must raid on each turn.