Pogs were originally a game played with milk caps which originated in Hawaii. The term Pog comes from POG brand juice.
Each player begins with their collection of Pogs (milk caps) and at least one slammer (a heavier playing piece). Players add an equal number (often just one) of Pogs to a face down stack and take turns attempted to overturn the Pogs by throwing their slammer at it. Pogs which are turned face up are collected by the thrower. The game continues in this manner until players run out of Pogs to add to the stack or until they voluntarily quit.