Futsal is a variant of association football played on a hard court, smaller than a football pitch, and mainly indoors. It can be considered a version of five-a-side football. Futsal is played between two teams of five players each, one of whom is the goalkeeper. Unlimited substitutions are permitted. Unlike some other forms of indoor football, the game is played on a hard court surface delimited by lines; walls or boards are not used. Futsal is also played with a smaller, harder, low-bounce ball. The surface, ball, and rules together favour ball control and passing in small spaces.