(one) is not playing with a full deck

(one) is not playing with a full deck

1. One is not mentally sound; one is crazy or mentally deranged. A: "Look at that guy talking to himself on the corner." B: "I reckon he's not playing with a full deck."
2. One is not very bright or intelligent. Jim's a nice guy, but with some of the foolish things he does, I wonder if he's not playing with a full deck.
See also: deck, full, not, play
Farlex Dictionary of Idioms.
See also:
  • not playing with a full deck
  • be not all there
  • be not all/quite there
  • be not playing with a full deck
  • be not (oneself)
  • not oneself
  • not feeling (oneself)
  • have a loose screw
  • have a few loose marbles
  • go crazy