Kabaddi is like high-stakes red rover — you don't want to get caught on the other side of the court.
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.
Sepak takraw is a high-flying sport combining volleyball and soccer.
Where it's popular: Southeast Asia, especially Thailand, Malaysia, Indonesia, Singapore, and Myanmar
How it's played: Sepak takraw is like a combination of soccer and volleyball. Like volleyball, players serve a ball over a net and try to ground it on the other team's side of the court. However, there are no hands allowed: You can only use your feet, head, knees, and other body parts. The ball is made out of a hard fiber called rattan.
How big is it? It's been a staple of the Asian Games since 1990.
Futsal is an indoor variation of soccer popular all over the world.
Where it's popular: Every continent
How it's played: Futsal is a variation of soccer played on a small, indoor court with a hard surface and a smaller, heavier ball. Unlike in soccer, futsal teams have five players each and can make unlimited substitutions.
How big is it? Futsal has a strong international presence, with world championships taking place every four years and continental championships roughly every two. It's becoming increasingly popular in American cities, as futsal courts are often easier to install than soccer fields.
Hurling is one of Ireland's great pastimes, and it's known as the fastest game on grass.
Where it's popular: Ireland
How it's played: Hurling has been compared to lacrosse, field hockey, and baseball. Teams score three points by knocking the ball into the net with a wooden stick known as a hurley, and they score one point by knocking it through the uprights above the goal. There is plenty of contact and even more danger — the ball moves 100 miles per hour, giving hurling the nickname "the fastest game on grass."
How big is it? Hurling is like a religion in Ireland and is one of the country's beloved national games. Outside of Ireland, hurling clubs are becoming more popular, especially in places with high Irish populations like New York and Boston.
Netball is like basketball without backboards or dribbling.
Where it's popular: Commonwealth countries, especially Australia, New Zealand, England, and Jamaica
How it's played: Netball is similar to basketball, with some key differences: Teams have seven players each, there is no dribbling, and the basket has no backboard. It's most popular as a women's sport.
How big is it? Netball is a fixture of the Commonwealth Games, and several countries have their own professional netball leagues. It's unlikely netball will surpass basketball in worldwide popularity anytime soon.
In the Afghani sport buzkashi, players on horseback try to toss a decapitated goat carcass into the 'circle of justice.'
Where it's popular: Central Asia, especially Afghanistan
How it's played: Buzkashi is not a game for the squeamish: Like polo, it involves players riding on horseback, but instead of a ball, it's the decapitated carcass of a goat or calf that they're trying to score with. Teams score by successfully depositing the carcass in the "circle of justice" — but have to be careful to avoid getting hit by a stray whip or boot-kick.
How big is it? Buzkashi is the national sport of Afghanistan, where it's been played for 600 years. In many towns, buzkashi matches are regularly held on Friday evenings.
Hornussen is a Swiss sport sometimes known as "farmer's golf."
Where it's popular: Switzerland
How it's played: Hornussen is a quirky sport occasionally referred to as "farmer's golf." Teams take turns striking a small rubber disk with a long, bendy club and get points based on where their ball lands. However, the defending team can steal points by intercepting the ball before it hits the ground.
How big is it? Hornussen is popular throughout Switzerland at the club level — there are 270 local clubs in the country today.
Chess boxing combines brains and brawn — you can win with a knockout or a checkmate.
Where it's popular: United Kingdom, Germany, India, Russia
How it's played: Chess boxing is the ultimate combination of brains and braun. Competitors square off in alternating rounds of boxing and chess, with the first person to successfully knock out or checkmate their opponent declared the winner. The idea came straight out of a comic book, but has since grown into a serious sport.
How big is it? There are chess boxing clubs in several countries, and there's even one in Los Angeles. According to the World Chess Boxing Organization, more than 800 people apply to participate in their championship fights.
In the caber toss, athletes lift a nearly 20-foot pole and try to flip it end over end.
Where it's popular: Scotland
How it's played: Caber tossing is a throwing sport, but in this case, the distance doesn't matter. Athletes must hoist a 19.5-foot, 175-pound pole and toss it in such a way that it turns end over end one time, lands perfectly on its top, and falls away from the thrower. A perfect throw takes a combination of strength and technique.
How big is it? The caber toss is a staple of the Highland Games held across Scotland each spring and summer.
Pato is the national sport of Argentina — it's like basketball on horses.
Where it's popular: Argentina
How it's played: A hybrid of sorts between polo and basketball, pato is played by two teams on horseback trying to throw a leather-handled ball through a circular hoop. "Pato" is Spanish for "duck," and earlier versions of the game used a live duck instead of a ball.
How big is it? Pato is known throughout Argentina, where it surprisingly is considered the national sport, above soccer. However, few Argentines actually play the game — there are only about 5,500 officially registered players in the entire country, and the vast majority of Argentines have never even seen a pato match.
Tejo is an explosive game that's like cornhole with more gunpowder.
Where it's popular: Colombia
How it's played: Tejo is essentially an explosive version of cornhole. Players take turns lobbing a metal disc down a narrow alley and try to hit a small ring on the other side. You get points for landing your disc closer to the target. But surrounding the target are triangular packets filled with gunpowder — hit one of those, and you'll be rewarded with a loud explosion, not to mention bonus points.
How big is it? Believe it or not, it's tejo that is the national sport of Colombia, not soccer. There are tejo competitions throughout the country, although it's mostly played at bars with the aid of a beer.