Where it's popular: India, Pakistan, Bangladesh, Nepal, Iran
How it's played: Kabaddi is sort of like a combination of red rover, tag, and wrestling. Teams take turns sending one raider across the court. That player scores one point for each member of the other team he tags, so long as he returns safely to his side of the court. But if the defending team manages to tackle the raider before he cross back to his side, the defense gets a point.
As for the length of each round, Kabaddi players have a unique way of keeping time: The raider must continually chant "kabaddi" without taking a breath — if the referee sees them inhale, their turn is automatically over.
How big is it? Pretty big. There are several professional kabaddi leagues in Asia, and it's been a regular at the Asian Games since 1990.