The buy-in is what a player pays to get into the game. At a cash table — blackjack, roulette, craps or poker — it is the money exchanged for chips, either at the table or at the casino cage. In a poker tournament, it is the entry fee, which buys a fixed starting stack and often includes a separate fee for the organiser.
Many tables set a minimum and maximum buy-in, often linked to the size of the blinds, and high-limit rooms may ask for much more. Check with the dealer or the table information before sitting down.
The buy-in is distinct from an add-on or a rebuy, which add chips later in an event under the tournament rules. In online poker and casino software, buy-in ranges, fees and currencies are configurable settings that operators adapt to each market and player segment.