a wild card

wild card

1. In a card game, a card that the player can choose to represent any card. He's going to play his wild card as an ace to win.
2. Someone or something that is unpredictable. He is too much of a wild card to be a successful candidate. Nobody wants to vote for someone wildly unpredictable. The wild card in this game will be the weather.
3. A person or team who is permitted to participate in an event or competition, such as a round of playoffs, without having to adhere to the usual entry protocol. The wild card rarely wins the championship, but anything is possible.
4. In computing, a character that is substituted for an unknown character in a search. An asterisk is often used as a wild card in database searches.
See also: card, wild
Farlex Dictionary of Idioms.

a wild card

You describe someone or something as a wild card when they cause uncertainty because nobody knows how they will behave or what effects they will have. Some Italians think of her as a possible wild card in next year's presidential election. Note: In games such as poker, a wild card is a card that can have any value a player chooses.
See also: card, wild
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • wild card
  • drawing card
  • a/your trump card
  • someone's trump card
  • trump card
  • card up sleeve
  • have a card up (one's) sleeve
  • have an ace up (one's) sleeve
  • have an ace up your sleeve
  • have got an ace up (one's) sleeve
References in periodicals archive
Tennis Association -- which runs a Grand Slam tournament, and so is not overseen by the WTA or ATP tours -- essentially can choose to ignore the eligibility rule and offer Gauff a wild card.
Open - which, as a Grand Slam tournament, is not overseen by the WTA or ATP tours - essentially can choose to ignore the eligibility rule and offer Gauff a wild card.
MARIA Sharapova is to be offered a wild card into the Aegon Classic in Birmingham next month, according to reports.
Andy Murray and Heather Watson, who herself will need a wild card into the tournament, have publicly express the view that doping offenders should not be given a helping hand on their return.
Andy Murray and Heather Watson, who herself will need a wild card into the tournament, have publicly expressed the view that doping offenders should not be given a helping hand on their return.
A player or team that has not qualified through the normal competitive channel receives a wild card entry.
The New York Yankees, Baltimore Orioles, Tampa Bay Rays, Detroit Tigers, Chicago White Sox, Oakland A's, and Los Angeles Angels are all battling for either a division title or to clinch a wild card in the American League.
However, Sania feels she had done enough to deserve a wild card as she will not figure in the top 10 of doubles rankings which will come out on June 11.
Ltd said, "In view of the exceptional response received from karting enthusiasts across the country, a Wild Card Selection Round was created to provide aspiring Formula 1 drivers with another opportunity to participate the country wide search.
India, July 7 -- Force India Formula One Team Academy today announced that it has extended the age range for participation in the One From A Billion Hunt via a wild card route.
What is a wild card? According to FUTURIST editor Edward Cornish, author of Futuring: The Exploration of the Future, a wild card is "an unexpected event that would have enormous consequences if it actually occurred."
That most likely would be a good enough mark to qualify for the playoffs as a wild card or as a division winner.
But when I hit Replace All, it replaces everything in the worksheet--not just the asterisks--because the asterisk is a wild card! It's a catch-22.
But what of Point Two--the idea that the inclusion of three division champs and a wild card team in each league will heighten the competitiveness and excitement of the pennant races?
Russian teenager Marat Safin has been given a wild card for Wimbledon after his progress as a qualifier in the French Open.