Va banque or Vabanque is a gambling term from the card game of Pharo or Faro, which was popular in the 18th and 19th century.
It is similar to the decision to "go bank" (or "banco") in chemin de fer, a form of baccarat.
It means that a player bets equal to the current amount of money in the game's "bank".
Vabanque is generally a risky choice in that the player puts everything at stake, he is "all in", and can lose everything, or gain an equal amount.
Va banque became a particularly noted expression due to its uses in a reported dialogue between Adolf Hitler and Hermann Göring as the Polish crisis reached its peak before World War II.