Marbles is a class of children's games played with glass, clay, or agate orbs generally approximately half an inch (1cm) across, but can range from very small (less than 1/4 inch), to very large (over 3 inches).
One version of the game consists of drawing a circle in the sand with a stick, and adhering to informally agreed upon rules, players will take turns at knocking marbles out of the circle with their own marbles.
A larger-scale game of marbles might involve taking turns to try and hit the opponent's marble to win. In this game, a useful strategy is to throw a marble such that it lands in a protected or difficult-to-reach location, should it miss.
As with many children's games, new rules are invented all the time, and each group is likely to have its own version of the game, often customised to the particular environment they play in.
Whilst adults rarely play marbles themselves, many engage in marble collecting, both for nostalgia and for the aesthetic appeal of the brightly coloured spheres, some of which border on art glass in quality.
