Risk permeates decision making because choice outcomes are often uncertain. When basing decisions on prior experience, previous research suggests that the prospects of gain and loss differentially produce subjective inflation and deflation of risk-associated values, respectively. These effects have been explained in terms of an “extreme-outcome rule”, which posits that valuations of risky options are biased towards the best/worst possible outcome. However, prior studies typically examined risky choices only at the 50% level, and it was unclear whether the risk-preferences predicted by the “extreme outcome rule” would generalize to other probabilities. Furthermore, the cognitive processes underlying risk preferences remained unclear. We addressed these questions through three pre-registered experiments where the critical condition involved decisions between equivaluable safe and risky options across three probabilities (20%, 50%, 80%) with the goals of either maximizing gains or minimizing losses. We found that probability and risk context mutually influenced choice-behavior: low probabilities were particularly subjectively inflated, leading to a strong preference for rare, risky options when seeking gains and a strong aversion when mitigating losses. We also found that decisions involving risk require more cognitive resources, as indicated by longer decision times. Additionally, a risk-sensitive reinforcement model showed that risk-seeking/averse individuals tended to overweight positive/negative outcomes. This study highlights that outcome uncertainty, the range of possible outcomes a given choice option could yield, is a critical component in probability distortion and that subjective probability distortions may drive risk attitudes.