The generalised or "folk" version of
Murphy's Law,
fully named "Finagle's Law of Dynamic Negatives" and usually
rendered "Anything that can go wrong, will". One variant
favoured among hackers is "The perversity of the Universe
tends toward a maximum".
The label "Finagle's Law" was popularised by SF author Larry
Niven in several stories depicting a frontier culture of
asteroid miners; this "Belter" culture professed a religion
and/or running joke involving the worship of the dread god
Finagle and his mad prophet Murphy.