In European roulette, the probability of hitting zero is based on the total number of outcomes on the wheel, which includes 37 numbers (1-36 and a single zero). The specific probability of landing on zero is calculated by taking the single winning outcome (zero) and dividing it by the total outcomes. This yields a probability of approximately 2.70%. This indicates that while hitting zero is less likely than hitting any of the other numbers, it remains a possible outcome in the game.