The simulation heuristic is a psychological heuristic, or simplified mental strategy, first theorized by Daniel Kahneman and Amos Tversky as a specialized adaptation of the availability heuristic to explain counterfactual thinking and regret.

According to this heuristic, people determine the likelihood of an event based on how easy it is to picture mentally. Partially as a result, people regret more missing outcomes that had been easier to imagine, such as "near misses" instead of when accomplishment had been much further away,

References

• Kahneman, D. & Tversky, A. (1982). The simulation heuristic. In D. Kahneman, P. Slovic & A. Tversky (eds.). Judgment under uncertainty: Heuristics and biases. Cambridge, UK: Cambridge University Press. pp. 201-210.