The World Series of Poker (WSOP) is "the oldest, largest, most prestigious, and most media-hyped gaming competition in the world".[2] It is held annually in Las Vegas. The first WSOP occurred in 1970 was an invitational wherein Benny Binion invited six of the best known poker players to The Horseshoe Casino. At first, the WSOP grew slowly. It took twelve years before the event drew 52 participants in 1982.[2] In the early 1980s satellites were introduced allowing people to win their way into the various events for less than the full entry fees.[2] By 1987, there were over 2,100 entrants into the tournament.[2] Participation peaked in 2006, with 8,773 people participating in the Main Event alone.[j]

The first World Series of Poker was not a freeze out tournament, but rather an event with a set start and stop time with the winner determined by secret ballot.[3] In 1973, a second event, five-card stud was added. Over the years most of the major poker variants have been played at one time or another. Since 2007, the WSOP has consisted of 55 events. While events traditionally take place over one or more consecutive days during the series in June and July, in 2008 the Main Event final table was delayed until November. The winner of each event wins a World Series of Poker bracelet and a monetary prize based on the number of entrants and buy-in amounts. A World Series of Poker bracelet is considered the most coveted prize or trophy a poker player can win, with one from the Main Event revered above all others.[4] Since 1976, a bracelet has been awarded to the winner of every event at the annual WSOP. WSOP victories prior to 1976 are also known as "bracelets". Most of the major poker variants are featured, though in recent years over half of the events have been variants of Texas hold 'em.

The series culminates with the $10,000 no-limit hold'em "Main Event", which since 2004 has attracted entrants numbering in the thousands. The victor receives a multi-million dollar prize. The winner of the World Series of Poker Main Event is considered to be the World Champion of Poker.[5]

Since its inception, Stu Ungar is the only player to have won the Main Event three times. Johnny Moss also holds three Main Event titles, however the first win was not played in the current tournament format but by a vote making Ungar the only three-time champion in terms of actual victories. Moss (if the first time win by vote is counted), Ungar, Doyle Brunson, and Johnny Chan are the only people who have won the Main Event for two consecutive years. Johnny Chan's second victory in 1988 was featured on the 1998 film Rounders. Phil Hellmuth holds multiple WSOP records: most bracelets (11), WSOP cashes (68) and most WSOP final tables (41).[6] The current Main Event bracelet winner, Peter Eastgate is the youngest person to win the Main Event.[7]