Perhaps you've strolled through Beijing parks this summer and noticed - perched between the recreational table-tennis players and the badminton players - groups of four or more people seated around small tables, staring intently at flat game boards, shouting and laughing as they flip tiles.
If so, you've just witnessed the popular Chinese game of mahjong in action.
The name means "sparrow", and there are myriad legends as to the game's origin. Some say it was developed by sparrow-catching soldiers in Jiangsu province; others trace the origins to aristocrats in Shanghai, and even to Confucius.
Regardless of when or where it started, today mahjong has legions of devoted fans across China, and abroad. There are several regional variations of the game, but the basic principles remain the same.
Mahjong, which is sometimes described as a metaphor for real life, involves a mix of strategy and luck. Typically in China, it also involves placing large or small bets.
A century ago, the game was mainly a pastime for wealthy people in China, but today mahjong is considered a game of the people.
When it was first introduced to the US in the 1920s, a craze for mahjong ensued. Eddie Cantor's popular song, Since Ma is Playing Mah Jong, improbably accompanied by ukulele strumming, even rose to the top of the music charts.
Mahjong is not an Olympic sport, but it has a worldwide following. The World Mahjong Organization was established in October 2005 and includes member organizations from China, Japan, US, Germany, France, Denmark, the Netherlands and Hungary.
Like a stringed instrument, mahjong is simple to learn, and difficult to truly master - providing endless opportunities for strategy, amusement and socializing.
Strategy for dummies
Don't be baffled by a mahjong master's mumbo jumbo because on a basic level this old Chinese pastime is a very simple game.
Just think of the popular card game gin rummy, and you'll be slapping the table and screaming out "mahjong" in no time. A gin rummy player collects a 10-card winning hand, and yells out "gin" when they complete a 10-card set. In mahjong, a player holds 13 tiles (or cards), and has to collect certain groupings of these pieces before they can win. When a player holds a winning hand 13 pieces, plus the new matching piece they pick up they yell out, "mahjong!"
Mahjong does not have kings, queens, jacks or aces. It has moon-cake-style circles and bamboo sticks instead. You keep picking up fresh pieces or can choose a piece discarded from the player on your right side.
The very best way to learn how to play mahjong is to sit with Chinese friends and ask them to play a demonstration game. Ask them to turn their pieces upwards so you can see what everybody is doing.
If you can explain to your Chinese friends that you're keen to play with them, they will be only too willing to help you learn this fun game. Happy mahjong playing.