Fanaticism can be described as the position that it's morally better to reject "a certainty of a moderately good outcome, such as one additional life saved" in favour of "a lottery which probably gives a worse outcome, but has a tiny probability of some vastly better outcome (perhaps trillions of additional blissful lives created)" (Wilkinson 2020). Some have argued that fanaticism should be rejected and that this might undermine the case for certain philosophical positions, such as longtermism.

See also the concept of "Pascal's mugging" (LessWrong 2020).