Bowls is a ball sport played mostly outdoors in summer on a flat grass surface called a green. Bowls can also be played indoors on artificial surfaces. The aim is to roll the larger balls, called bowls, closest to the smaller yellow or white ball, called the jack. Bowls can be played as singles or in teams of two to four players. Bowls Tasmania encourages participants with a disability to join a club in their local area. Competitions range from social bowls through to the Multi-Disability Lawn Bowls National Championships. Physical Disability Sport Tasmania and New Horizons Tasmania also run bowls programs for participants with a disability.