Pascal's mugging refers to an apparent paradox in decision theory, named in analogy to Pascal's wager. An agent with an unbounded utility function can potentially be exploited by bets offering tiny probabilities of vast utilities: describable utilities can get large faster than the probabilities of corresponding situations given by the Solomonoff-like priors get small. The situation is dramatized by a mugger:
Now suppose someone comes to me and says, "Give me five dollars, or I'll use my magic powers from outside the Matrix to run a Turing machine that simulates and kills 3^^^^3 people."
Intuitively, one is not inclined to acquiesce to the mugger's demands, and yet it's not clear how this intuition can be justified in decision theory.
- Nick Bostrom (2009). "Pascal's Mugging". Analysis 69 (3): 443-445. (PDF)