Someone whose behavior is unknown, or something with an unknown effect
“The newly elected judge is a wild card; no one knows his political views.”
In the cards
Very likely to happen
“It looks like Kitayama-san’s return to the stage as an orchestra conductor isn’t in the cards.” Note: This is a reference to Tarot cards or other cards used to predict the future
Put one’s cards on the table
To tell someone the truth about one’s feelings or plans
“It’s time to put our cards on the table. I think the proposed expansion is a good idea.” Note: In some card games, players lay their cards out face up for the other players to see.
Play one’s cards right
Use one’s skills carefully to win
“Yasuda-san, if she plays her cards right, could be the next vice president of operations.”
A card
One who knows how to make others laugh
“You’ll enjoy working with Ishida-san. She is quite a card.”