A decision support system comprises a decision repository with at least one stored game play decision for a particular hand held by a player and a corresponding first card held by a dealer, in a game of blackjack, and a programming facility operable, selectively, by the player to amend the at least one stored game play decision. The decision repository has a stored game play decision for every possible combination of a particular hand held by the player and corresponding first card held by the dealer. The stored game play decision is a recommended game play decision for the player, namely a decision to hit, to stand, to split to double, or to surrender