At each end of the court—usually about 92 ft (28 m) long and 50 ft (15 m) wide—is a bottomless basket made of white cord net and suspended from a metal ring, 18 in. (46 cm) in diameter, which is attached 10 ft (3.05 m) above the floor (usually hardwood) to a backboard made of fiberglass, wood, or other material. Players may throw, dribble (bounce), or shoot the basketball (an inflated ball usually made of leather or rubber) but may not run with it or kick it.

Teams try to advance the ball and shoot it through one basket (the ball must enter from above) and to keep the opposition from scoring through the other. Each field goal, or basket, scores two points, or three points if shot from beyond a specified distance (21 ft/6 m in U.S. colleges, slightly longer in international and professional play). Teams must shoot the ball within a prescribed time limit (24 sec in the National Basketball Association; 30 sec in international games and in most women's play; 45 sec in men's collegiate play).

Any player making illegal body contact with an opposing player is assessed a foul; the opposing team may be given possession of the ball, or an opposing player awarded free throws at the basket from the foul line. Each made foul shot is worth one point. Players who exceed the foul limit (usually five, but six in the NBA) are disqualified from the game. International and collegiate basketball games have two 20-min halves, professionals play four 12-min quarters, and high schoolers play four 8-min quarters.

Professional basketball began (1896) in New York City and was at one time played on courts enclosed by wire mesh (basketball players are still occasionally referred to as "cagers" ). Until the 1950s it languished in popularity behind college basketball and such touring black teams as the Harlem Globetrotters and the New York Rens.

The merger (1949) of the National Basketball League and the rival Basketball Association of America into the National Basketball Association (NBA) led to greater popularity. The appearance of stars like George Mikan, the signing of black players beginning in 1950, the temporary disrepute of the college game owing to gambling scandals in the early 1950s, and the adoption of the 24-sec shot clock in 1954, further boosted the NBA.

Its success inspired the formation of several competing leagues, among them the American Basketball Association (ABA), founded in 1967 and merged into the NBA in 1975. In the 1980s the emergence of charismatic players like "Magic" Johnson (see Johnson, Earvin), Larry Bird, and Michael Jordan, combined with aggressive marketing, made the NBA hugely successful, so that basketball often seemed the premier U.S. professional sport. A labor dispute in late 1998 delayed and shortened the 1999 season.

Basketball is a major sport in U.S. colleges. Postseason tournaments, first the National Invitation Tournament (begun 1938) and then the National Collegiate Athletic Association (NCAA) championships (begun 1939), soon attracted enough attention to fill large arenas like New York's Madison Square Garden. Point-shaving and game-fixing scandals unsettled college basketball in both 1950–51 and 1961, but did not diminish fan loyalty for extended periods.

The NCAA championship tournament, once secondary to the NIT, grew enormously from the 1960s into the 1990s. Large live audiences, national television coverage, and competitive parity have helped to make the NCAA's "March Madness" and Final Four (the semifinal and final rounds of the tournament) one of the most popular of all U.S. sporting events.

An exhibition match was played at the 1904 Olympics, but basketball did not become an official part of the games until 1936. International rules and court dimensions differ slightly from U.S. standards. Still, the United States outclassed the rest of the world until 1972, when the Soviet Union defeated the U.S. team for the gold medal (despite American protests that the Soviets had been allowed to score a basket after the game had ended). In the 1980s, many nations achieved parity with the United States, which was still fielding a team of collegians. The U.S. Olympic Committee therefore assembled for the 1992 games a "Dream Team" composed of one collegian and the finest professional players, who handily won the gold medal.

Women's basketball has grown rapidly since the 1970s. Until then, women and girls had been allowed to play only a six-player game in which offensive and defensive players were rooted to one half of the court. Today full court action in women's college competition and in the Women's National Basketball Association (since 1997) exhibits advanced skills and fast-paced play, and has attained wider popularity than many other women's sports.

See P. Axthelm, The City Game (1971); D. Smith, Basketball—Multiple Offense and Defense (1982); A. Wolff, 100 Years of Hoops (1991); The Official NBA Basketball Encyclopedia (2d ed. 1994).