Definify.com

Definition 2024

(idiomatic, chiefly US and Canada, of a person) To behave in a manner suggesting that one is of normal intelligence, alert, and mentally stable.
- 1987 April, Barbara Ehrenreich, “The Unfastened Head of State”, in Mother Jones, volume 12, number 3, page 10:
  Someday our grandchildren will look up at us and say, "Where were you, Grandma, and what were you doing when you first realized that President Reagan was, er, not playing with a full deck?"
- 2009, Julie Lyons, Holy Roller, ISBN 9780307457899, ch. 1 (Google preview):
  [E]very single person, who Grandma said were family members, appeared to be either mentally ill, retarded, or strung out on drugs. Grandma seemed to be playing with a full deck, but no one else was.
- 2014 June 4, Cary Shuman, "Former Chelsea High Football Standout and Pop Warner Coach Joe Leonard Dies at 84," Chelsea Record (US) (retrieved 14 Oct 2015):
  “My father’s favorite saying was, ‘Are you alright?’ and ‘Are you playing with a full deck?’” recalled Darren.
(team sports) To play a game with the availability of a team's full roster of players.
- 2014 Nov. 24, Fred Mitchell, "Monday's recap: Bulls 97, Jazz 95," Chicago Tribune (retrieved 14 Oct 2015):
  The Bulls were closer to playing with a full deck Monday night when coach Tom Thibodeau announced that Derrick Rose and Pau Gasol would be in the starting lineup.

(Sense: behave in a manner suggesting normal intelligence): Almost always used with the present participle and in negative constructions—not playing with a full deck—meaning "behaving in a manner that is odd, suggestive of diminished mental capacity, or not altogether sane".