Research on gambling near-misses has shown that objectively-equivalent outcomes can yield divergent emotional and motivational responses. The subjective processing of gambling outcomes is affected substantially by close but non-obtained outcomes (i.e. counterfactuals). In the current paper, we investigate how different types of near-misses influence self-perceived luck and subsequent betting behavior in a wheel-of-fortune task. We investigate the counterfactual mechanism of these effects by testing the relationship with a second task measuring regret/relief processing. Across two experiments (Experiment 1, $n$ = 51; Experiment 2, $n$ = 104), we demonstrate that near-wins (neutral outcomes that a reclose to a jackpot) decreased self-perceived luck, whereas near-losses (neutral outcomes that are close to a major penalty) increased luck ratings. The effects of near-misses varied by near-miss position (i.e. whether the spinner stopped just short of, or passed through, the counterfactual outcome), consistent with established distinctions between upward versus downward, and additive versus subtractive, counterfactual thinking. In Experiment 1, individuals who showed stronger counterfactual processing on the regret/relief task were more responsive to near-wins and near-losses on the wheel-of-fortune task. The effect of near-miss position was attenuated when the anticipatory phase (i.e. the spin and deceleration) was removed in Experiment 2. Further differences were observed within the objective gains and losses, between “clear” and “narrow” outcomes. Taken together, these results help substantiate the counterfactual mechanism of near-misses.