Abstract: There are provided a game system, game machine, game data distribution machine, image data distribution system and computer available information which can synchronize clock signals between a plurality of devices. A game data distribution machine (100) includes a machine clock generation section (180), a clock selection section (160) and a clock generation section (120). By using these sections, a reference clock is generated as a basis of synchronization. The game data distribution machine also includes a clock and data superposition section (170) which superposes the reference clock on a game data, the superposed game data being then distributed to game machines (200). Each of the game machines (200) includes a clock and data separation section (272) which extracts the reference clock from the superposed data and a clock generation section (220) which generates an operation clock for each of game execution means including a game data production section (290) and so on, based on the reference clock.