Two teams of at least... oh say five people line up holding hands across from one another at a distance of roughly twenty-five feet. The team going first decides on a member of the opposing team and calls out "Red Rover Red Rover send [person's name] right over." The person called leaves their team and runs toward the opposing team as hard and fast as they can in order to try and break through the line of the other team. If they are sucessful they return to their home team taking with them a member from the opposition of their choice who will now serve their team. If they are unsucessful they are incorperated into the opposing teams force. The game is played until the last link of one team is broken.
I remembered Red Rover as a fairly tame school yard game.
The game changes a lot when a ragingly drunk two-hundred and fifty pound transsexual is hurling all of their genderbending fury at you in a die to win speed pace*.
For it's simplicity, Red Rover is a really fun and engaging game. To win you need a strategy to manage your resources [people] in the best way; you want the strongest people on your team but if you call them over and they break your ranks you may have to sacrifice your strongest player. Loyalty also became an interesting element of the game to follow- where there wasn't supposed to be lingering team loyalty, players developed ways of manipulating the game by 'wimping out' in order to be reclaimed by their original team.
A good game modification could be to turn it into a drinking game where instead of calling someone over order that the other team have a shot.
*don't play grown-up Red Rover without insurance, we sustained a number of injuries.