Game: Kill the king
This game uses any number of teams with any amount of players for each team. One person on each team is considered the king (or queen). The king must stand out in some way whether it be a crown, herald, etc. Battle commences and each team is trying to kill the opposing team's king, while at the same time keeping their own king alive. When a king is killed, he shouts out his name, and all the other fighters on his team die with him. The team who's king is the last standing wins.
Variation: Instead of allowing each team to know who the other kings are, have each team pick their king in secret before hand. Now you must try and figure out who a teams king is depending on how they protect their team members.