English

Noun

mug's game ‎(plural mugs' games)

1. (idiomatic) A foolish, profitless, or hopeless undertaking.
   • 1988 May 20, Strobe Talbot, "Inside Moves," Time:

     The sheer destructiveness of nuclear weapons makes the quest for defenses a mug's game.

References

• “mug's game” in Dictionary.com Unabridged, v1.0.1, Lexico Publishing Group, 2006.
• "mug's game" at Rhymezone (Datamuse, 2006)
• Oxford English Dictionary, second edition (1989)