not playing with a full deck

not playing with a full deck

1. Not mentally sound; 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. Not very bright or intelligent; dimwitted. 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.

not playing with a full deck

mentally deficient. North American informal
A deck in this phrase is a pack of playing cards.
See also: deck, full, not, play
Farlex Partner Idioms Dictionary
See also:
  • (one) is not playing with a full deck
  • be not playing with a full deck
  • be not all there
  • be not all/quite there
  • be not (oneself)
  • not oneself
  • not feeling (oneself)
  • have a loose screw
  • have a few loose marbles
  • not have all (one's) marbles