There is the old classic joke
about the cowboy who plays
in a game he knows is fixed.
When asked why he plays in a
game he can't beat, his response is...

It's the only game in town!

The Birth of Poker

The playing cards that are used to play Poker are "Court Cards." They arrived from Europe and are called that because the "face" cards feature people you would find in a Royal Court (King, Queen, etc).
Poker is often associated with the saloons of the "Old West" in the United States. Most likely, the history of the game in America started in New Orleans, where it was played by immigrants from Europe. The game played on those days is different that the variations of Poker that are played today, but betting and bluffing are at the basis of every Poker game.
In Poker, the objective is to use the cards you are dealt to make a "hand," which is a set of cards (usually five) with a certain rank. The rank of the hand is closely related to the probability of getting such a hand (higher rank, lower chances).
Each player may bet money on his victory (meaning, his will rank the highest when all hands are revealed). To stay in the round and to have a chance to win the money, each player must match the betting of all his fellow players (this is referred to as "calling the bet"). If you think your opponent has a stronger hand, you may choose to fold, meaning you lose the ability to win the hand, but you also don't risk anymore money.
The beauty of the game is the famous "bluff." Meaning that if you think your opponent has you beat, you may also choose to place a higher bet that will make your opponent fold, making you the winner even though your hand is actually the weaker one.
This combination of gambling and lying, with the Old West's tradition of whiskey and guns, is what creates the folklore of Poker in that time and place.

Gambling in Ohio, 1874
legendsofamerica.com

By far the person who embodies most the spirit of Poker in the Old West is "Wild Bill Hickok" (b. 1837 as James Butler Hickok). As a gunfighter, lawman, and a soldier in the Civil War, he participated in several well-known shot-outs and fights, and thus became a living legend.
Gradually, he became more famous for being involved with gambling and women than for keeping the peace at the town of Abilene where he was sheriff. Eventually Bill traveled to Deadwood, South Dekota where he hoped to make a fortune finding gold. Hickok ended up spending more time in the saloons playing Poker and drinking. One day he beat a man named Jack McCall at poker.
The next day, Bill was drinking and playing Poker with his back to the saloon's entrance. McCall entered the saloon and shot Wild Bill in the back. This was the end of the Wild West legend. It is said that the hand he was holding at the time was some combination of Eights and Aces, and to this day a hand made with those cards is refered to as "Dead Man's Hand."
Like many other famous gunfighters of the Old West, many stories were told about him after his death. We can't know for sure now which ones are true. Since then he was portrayed in countless books and in many TV shows and movies.

Statue of Will Bill in South Dakota
Photo by Randy Peters
(CC-by-nc license)

Years after the days of Poker in the Old West, but still before the game and its stars became house-hold names, there was a card player called Stu Ungar.
Stu was born to Jewish parents in New York in 1953 and when he was 13 his father died of a heart attack. Stu dropped out of school and started to play cards to support his mother.
Stu's gift was patroned by a local mobster. Initially his game was not poker but rather "Gin Rummy." He played for money of course and started winning. After a while, he found it more and more difficult to find someone who was willing to bet against him and that is one of the reasons switched to Poker.
During his career, Stu Ungar won the WSOP three times, which remains the highest record to this day. Ungar, nicknamed "the Kid," is considered by many to be the best Poker player there ever was. His ability to calculate odds and "read" opponents (sense what cards they're holding) is considered unmatched by any other player.
With these kind of skills in a field most consider ruled by chance, Ungar could have made a fortune. However he spent the money he earned on sports betting and drugs. He would win money at the tables, and spent it away from them. When he died of a cocaine overdose in the age of 45 he had less than US$1000.
He is the subject of several books and a movie was made about his life.

Stu Ungar