What it means
A cheeky way to say someone’s acting clueless, confused, or a bit out of it. You’re comparing their brain to a deck of cards with a few missing, so the game can’t work properly. It can sound pretty harsh if you mean they’re stupid, but it’s also used as a half-joking reaction to a truly ridiculous decision.
Usage examples
"Dude tried to update his laptop by putting it in the freezer, then wondered why it wouldn’t turn on. He’s not playing with a full deck."
"Anyone who pays full price for that on the same day it goes on sale is not playing with a full deck."
"He tried to pay the bus fare with a loyalty card from the bakery, bless him, not playing with a full deck that morning."
Other ways to say it
Editors of this term
Your vote counts
Is this real street talk or have we lost the plot? Cast your vote.