Card counting is a term used in blackjack that refers to counting cards and remembering what cards have been played. Exceptionally skilled players use it in order to calculate their odds and get an advantage over the dealer by trying to guess what card is going to be dealt next.
While it does sound amazing, card counting is no ordinary feat and takes a lot of knowledge and practice. Furthermore, even those who know how to count cards don’t always win.
One thing to note is that card counting isn’t technically illegal, but if you are caught doing it you could be asked to leave the premises of a brick-and-mortar casino. To prevent players from counting cards, many gambling establishments use multiple decks of cards for blackjack and shuffle them regularly. Some do it even after each round.