The gamble feature in Book of Ra Deluxe is a 50/50 card color prediction game available after every base game win. Correct guesses double the payout up to five consecutive times.
After any winning spin in the base game, a Gamble button appears. Pressing it reveals a face-down playing card. The player selects either red or black. A correct guess doubles the win. An incorrect guess forfeits the entire payout — not just the doubled portion. The gamble is not available during free spins or autoplay.
Each guess has a 50% success rate. One correct guess doubles the win (2×). Two consecutive correct guesses produce 4×. Three produce 8×. Four produce 16×. Five produce 32×. The probability of reaching 32× is 0.5^5 = 3.125%. The expected value of any gamble attempt is exactly zero — the 50% chance of doubling balances the 50% chance of losing. The gamble does not affect the slot's RTP.
The gamble can be repeated up to five times per win. After five successful guesses, the win is automatically collected. There is no option to collect a partial amount during the gamble — the player either continues doubling or takes the current total. The previous five card results are visible on screen, though each draw is independent and past results have no predictive value.
The gamble is a personal risk preference decision, not a strategy tool. Some players gamble small base game wins (under 5× bet) once to double them, accepting the 50% loss risk on a minor amount. Gambling large wins or bonus round payouts carries significant downside. A $200 free spins payout gambled once has a 50% chance of becoming $400 and a 50% chance of becoming $0. The house edge on the gamble itself is zero, but the opportunity cost of losing an existing win is real.