Decision-making involves weighing up the outcome likelihood, potential rewards, and effort needed. Previous research has focused on the trade-offs between risk and reward or between effort and reward. Here we bridge this gap and examine how risk in effort levels influences choice. With outcome uncertainty, people’s risk attitudes follow a fourfold pattern, varying with the domain (gains or losses) and probability (rare or common). Three experiments assessed people’s risk attitudes for money, physical effort, and mental effort. With monetary gambles, risk attitudes followed the classic fourfold pattern, and people were risk averse for increases in money (gains). With both physical and mental effort, however, people exhibited a “flipped” fourfold pattern of risk preferences and were instead risk seeking for increases in effort. Overall, these findings indicate that people treat effort as a loss of resources and are more willing to take risks to avoid potentially high levels of effort.