Softball is a variant of baseball played with a larger ball on a smaller field. It was invented in 1887 in Chicago, Illinois, United States as an indoor game. It was at various times called indoor baseball, mush ball, playground, softball, kitten ball, and because it was also played by women, ladies’ baseball. The name softball was given to the game in 1926, because the ball used to be soft. There are three types of softball. In the most common type, slow-pitch softball, the ball, which can measure either 11 or 12 inches in circumference depending on the age and league, must arch on its path to the batter, and there are 10 players on the field at once. In fastpitch softball, the pitch is fast, there are nine players on the field at one time, and bunting and stealing are permitted. Modifiedsoftball restricts the windmill windup of the pitcher, although the pitcher is allowed to throw as hard as possible with the restricted back swing. Softball rules vary somewhat from those of baseball. Two major differences are that the ball must be pitched underhand—from 46 ft (14 m) for men or 43 ft (13.1 m) for women as compared with 60.5 ft (18.4 m) in baseball—and that seven innings instead of nine constitute a regulation game. Despite the name, the ball used in softball is not very soft. It is about 12 in (30.5 cm) in circumference (11 or 12 in for slow-pitch), which is 3 in (8 cm) larger than a baseball. Softball recreational leagues for children often use an 11-inch ball. The infield in softball is smaller than on an adult or high school baseball diamond but identical to that used by Little League Baseball; each base is 60 ft (18 m) from the next, as opposed to baseball’s 90 ft (27 m). In fast pitch softball the entire infield is sand, whereas the infield in baseball is grass except at the bases which are sand.

A softball game can last anywhere from 3 to 7 innings, or 1–2 hours depending on the league, rules, and type of softball; however 7 innings is the most common. In each inning, each team bats until three batters have been put out (see below). The teams take turns batting. Officially, which team bats first is decided by a coin toss, although a league may decide otherwise at its discretion. The most common rule is that the home team bats second. Batting second is also called “last at-bat”. Many softball players prefer to bat second because they feel they have more control in the last inning, since they have the last at-bat. In the event of a tie, extra innings are usually played until the tie is broken except in certain tournaments and championships. If the home team is leading and the road team has just finished its half of the seventh inning, the game ends because it is not necessary for the home team to bat again. In all forms of softball, the defensive team is the fielding team; the offensive team is at bat or batting and is trying to score runs.