Milk caps is a children's game played with flat circular cardboard milk caps. Players make a stack of these caps, and take turns to drop a heavier "slammer" object onto it, causing the caps to be disrupted.
Each player keeps any face-up caps and is to restack the face-down caps, repeating the process until none land face-down, at which point the player who collected the most caps wins the game of milk caps.
The game is also known as Pogs, under which name it was sold commercially in the 1990s. The name originates from Pog, a brand of juice made from passionfruit, orange, and guava; the use of the juice's caps to play the game preceded the game's commercialization.[1]