Jacks-metal

Knucklebones, or Jacks, is a game of very ancient origin, played with usually five small objects, originally the "knucklebones" (actually the astragalus: a bone in the ankle, or hock) of a sheep, which are thrown up and caught in various ways. Modern knucklebones consist of six points, or knobs, proceeding from a common base, and are usually made of metal or plastic. The winner is the first player to successfully complete a prescribed series of throws, which, while of the same general character, differ widely in detail. The simplest consists in tossing up one stone, the jack, and picking up one or more from the table while it is in the air; and so on until all five stones have been picked up. Another consists in tossing up first one stone, then two, then three and so on, and catching them on the back of the hand. Different throws have received distinctive names, such as riding the elephant, peas in the pod, and horses in the stable.

As with many children's playground games, the game is known by a wide variety of names including astragaloi, hucklebones, dibs, dibstones, jackstones, chuckstones, five-stones jackrocks, onesies, jax, kugelach, batu seremban, or snobs.

-wikipedia