An action card in poker is a community card that stands to generate a lot of betting and raising. The term is usually used to describe a turn or a river card that significantly changes the board structure.
For example, after a flop of Kh6h4s, the 5h appearing on the turn is an action card. This particular card completes a flush draw and a couple of different straight draws, thus significantly changing the board.
An action card will often improve one or more players involved in a hand, leading to more raising or even overbetting. But even when this isn’t the case, experienced players and maniacs will utilize the notion of an action card to start bluffing, representing a strong holding.
