Casino poker tokens (also known as chips, checks or cheques) are small discs used in lieu of currency in casinos. Colored metal or compression molded clay tokens of various denominations are used primarily in table games, as opposed to metal token coins, used primarily in slot machines.
Some casinos also use gaming chips for high stakes table games ($25,000 and above). Plaques differ from poker chips in that they are larger, usually rectangular in shape and contain serial numbers.
Although the first gambling house was legalised in Venice in 1626, actual poker chips as we know them now were still not used for over two hundred more years. Back in the 1800s and prior, poker players seemed to use any small valuable object imaginable. Early poker players sometimes used jagged gold pieces, gold nuggets, gold dust, or coins as well as "chips" primarily made of ivory, bone, wood, paper and a composition made from clay and shellac. Several companies between the 1880s and the late 1930s made clay composition poker chips. There were over 1000 designs from which to choose.
After slow but steady gains in popularity throughout the 20th century, hold 'em's popularity surged in the 2000s due to exposure on television, on the Internet, and in popular literature. During this time hold 'em replaced 7 card stud as the most common game in U.S. casinos, almost totally eclipsing the once popular game. The no-limit betting form is used in the widely televised main event of the World Series of Poker (WSOP) and the World Poker Tour (WPT).
Because each poker player only starts with two cards and the remaining poker cards are shared, it presents an opportune game for strategic analysis (including mathematical analysis). Hold 'em's simplicity and popularity has inspired a wide variety of strategy books which provide recommendations for proper play. Most of these books recommend a strategy that involves playing relatively few hands but betting and raising often with the hands one plays.