A medium-sized group of children (around 30 or so) are divided into two equal teams. Older kids and adults can play with younger kids, but the two sides should be divided about equally in terms of their ability to run fast.
The game is played across an open field. Each team draws a line at opposite sides of the field. Behind the line is "safe". Between the two lines, in the middle of the field, is a sort of no-man's-land. The trick is, the last one to leave his or her respective safe line can tag the one who came out from the other side sooner. In other words, if I am on the opposite team from you, and I see you leave your line, I can come out from my line and tag you. Meanwhile, however, others can come out from your side and tag me. This is where the "Dare" comes in. If I am a fast runner, I may come out from behind my safe line, and edge closer and closer to your safe line, to see if I can dare someone on your team into chasing me back toward my own side of the field. If I can run fast enough, people from my own team can come from my line and save me by tagging you when you get close enough, since they would come out from their line after you came out from yours. Once a person gets tagged, the person who tagged that person is safe until he returns to his own safe line and comes back out.
What happens when a person gets caught gives rise to two different versions of this game. In one version, each side has a "jail", consisting of people strung out into the middle of the field from the safe line. As more and more people from the opposite side get caught, the "jail" line gets longer and longer, and it becomes easier and easier for someone to "rescue" the member of their team at the end of the jail line by tagging them before getting caught. In the other version, people who get caught simply join the other side. This makes the game finish faster, since everyone eventually winds up on one side.
This game can give rise to all sorts of interesting mayhem. It is fairly common for two kids to both run back toward their home lines when they get close to each other in the middle of the field, since neither child is sure if he came from his line last. It is also common for two kids from opposite sides to run directly together in the middle, both convinced they came from their respective sides last, and both claiming the other person should be tagged. Another common scenario is for a fast runner to draw two or three people off of the opposite line, who then chase him pel-mel toward his own side, but cannot catch him in time to avoid being caught themselves. This game has simple rules, but isgreat fun.