A “wild card game” is called that because it features teams that reached the playoffs via a wild card spot instead of by winning their division or qualifying automatically. Those teams are essentially extra entrants added to the bracket, so the games they play are labeled “wild card games.”

What “wild card” means

  • In sports, a wild card is a playoff spot given to a team that did not qualify by the standard route (like winning its division or conference) but still had one of the best remaining records.
  • The games involving these extra qualifiers, especially the opening round of the postseason, are therefore called wild card games or a wild card round.

Origin of the term

  • The phrase comes from card games such as poker, where a “wild card” can stand in for any card and change the outcome unexpectedly.
  • Sports borrowed the term in the mid‑20th century to describe a nonstandard or flexible way for extra teams to enter competition, emphasizing their unpredictable impact on the bracket.

Example: MLB and NFL

  • Major League Baseball uses “wild card” for postseason berths given to teams that did not win their division but had strong records; the opening postseason round is officially called the Wild Card Series (formerly Wild Card Game).
  • The NFL adopted a wild card format in 1970, adding playoff spots for non‑division winners and labeling that initial weekend of playoff matchups the wild card games or wild card round.

In short: it’s called a wild card game because it’s the playoff game (or series) involving those extra, non‑automatic qualifiers—teams that function like “wild cards” added to the tournament field.