It is a common misconception that card counting is illegal in the United States.  The stipulation allowing it to be a legal practice in casinos is that the only thing being used to count the cards is the player’s mental ability to do so.  The assistance of other players, computer program, or other machine (not that you could pull that off in a casino anyway) is what makes the card counting practice illegal.

If card counting is legal then why are we not all gambling professionals robbing casinos legally?  Well, the answer is simple.  More or less, the practice of card counting is typically overcomplicated by the average person, and therefore either not used in gambling, or not executed properly enough to render the results we want to see.  To further complicate the matter for the players who wish to learn how to count cards, there are several different tactics that you can use to count the cards, and the way you focus on counting the cards will differ with each different card game you play, and may become more difficult for the player to track after playing successive hands.  Counting the cards becomes increasingly difficult for the player as the number of decks being used in game play is increased; and many casinos never rely on one deck at a time!

If you want to learn how to count cards, then you should find a simple method to learn; and learn a few different ones.  Realize that the concept is simple, but that it must be perfectly executed to be most effective.  More often than not, the edge that you get over the house is negligible, and does not increase much even with a perfect deployment of the technique.

If you are counting cards and the casino feels as though you are harming their advantage, then you may experience some hassle about it.  If this happens to you, never admit that you were counting cards; do not touch any employees, leave without creating a scene and without showing identification.  Casinos cannot detain you without suspicion of criminal activity.  Provide your name to prevent obstruction of justice, and follow the other suggestions to avoid being accused of a crime (if you create a fuss, or touch an employee, they can throw something on you!)  At most, you can be barred from the casino for counting cards (yes, legally) because discrimination only covers classifications based on things like age, sex, race, and disabilities.