Game: The first game is called PDQ, or Pretty Darn Quick. This is an incredibly popular parkour game, where the basic objective is to jump on peoples' feet. This is actually one of the more complicated games, it usually takes a practice game for everyone to get the hang of it. I often play a “demo game” as I'm teaching it, so people can see the rules and their effects.
Rules: You start in a circle and everyone puts one first in the center. Someone (usually the winner of the last game) picks a random person, taps their fist, and counts “one,” moves to the next person in the circle, “two” and so on until everyone has been numbered. Once everyone has a number, everyone shouts “One, two, three, PDQ!” and everyone simultaneously takes one jump away from the center.
At this point, you continue in number order (“one” is first, “two” is second, etc). When it is your turn to go, your goal is to jump on someone else's foot. No one can move until you are in the air, however. If you feint and pretend to jump and someone else moves their feet, then they are eliminated. If you jump and land on someone's feet, they are eliminated.
The interesting twist to this game is... you can only jump when the person who is “it” is in the air. However, if you jump and land on someone else's feet, you can still get them out even though it isn't your turn.
Goal: The game continues until only one person remains.
Example Game: John, Sue, Peggy, and Roger are playing PDQ. John is player #1, Sue is player #2, Peggy is player #3, and Roger is player #4.
Round #1: John jumps into the air and lands on Roger's left foot. Roger is out. Sue and Peggy both jump away from John.
Round #2: Sue jumps towards John, but John jumps towards Peggy and lands on her feet. Peggy is out.
Round #3: John feints, but Sue doesn't fall for it. John then jumps, but Sue jumps straight up and lands on John's feet. John is out. Sue wins the game.
Physical Benefits: This game is nothing more than jumping, but it turns it into a very enjoyable and competitive game. It's not highly physically demanding, but it is a great method of training for jumping, as well as precision landings.
Other Benefits: This is quite a fun game because it is actually a bit taboo. We've always been told not to step on people's feet... but now we're supposed to! If you present it to kids this way, they can get really excited about it. This is also a very flexible game; it can be scaled to any number of people. I've played with only my sister, and then I've played a game with 45 other people. The more people there are the more hectic it gets, with people jumping at you from all directions.