Kabaddi is an ancient Indian sport that plays like a combination of capture the flag and red rover. The field is divided into two and teams take turns sending one of their men over (the Raider) to the other side with the intent to tag an opposing player (the Raid) and then run back to their own side before the other team can stop the Raider. If the Raider makes it back in 30 seconds, his team scores a point. If the other team can keep the Raider from returning, they score a point.
Simple, no?
Current.com has a nice little documentary video on the sport, which is gaining popularity in America, but if you don't have time for that, there's this:
Actually, there are probably better videos out there. That one kinda looks like a mugging at the beach, first in fastmo and then in slowmo.
The thing that seems to be lost in modern Kabaddi is the rule that requires the Raider to hold his breath and chant "kabaddi" over and over during the raid. Instead, they've replaced it with this 30 second rule thing, which might make it easier to officiate, but completely takes away the fun of hearing somebody go, "kabaddikabaddikabaddikabaddikabaddi..."
More info at kabaddi.org.