Abstract People spend a considerable amount of their time mentally simulating experiences other than the one in which they are presently engaged, as a means of distraction, coping, or preparation for the future. In this integrative review, we examine four (non‐exhaustive) cases in which mentally simulating an experience serves a different function, as a substitute for the corresponding experience. In each case, mentally simulating an experience evokes similar cognitive, physiological, and/or behavioral consequences as having the corresponding experience in reality: (i) imagined experiences are attributed evidentiary value like physical evidence, (ii) mental practice instantiates the same performance benefits as physical practice, (iii) imagined consumption of a food reduces its actual consumption, and (iv) imagined goal achievement reduces motivation for actual goal achievement. We organize these cases under a common superordinate category and discuss their different methodological approaches and explanatory accounts. Our integration yields theoretical and practical insights into when and why mentally simulating an experience serves as its substitute.