“It was an odd caprice of fate that an actor who would have preferred doing classical texts made his fame and fortune in something based on a comic book.”
“The Board will require that this privilege be used with moderation, and will not sanction individual variations which are due to caprice.”
“There are vast schemes, abandoned because of some caprice. There are secrets which everybody knows and no-one speaks of.”
capriccio
A sudden and unexpected or fantastic motion; a caper (from same etymology, see below); a gambol; a prank, a trick.