Is It Illegal to Count Cards in Casino Games? 7 Things You Should Know
Is counting cards illegal? While it’s not, casinos often ban the practice. They say the house always wins, but card counting challenges that. Read on to find out why casinos don’t allow it.
Updated January 24, 2025.
In this article
1. What Is Card Counting?
2. The Math Behind the Card Counting Method
3. Famous Card Counters: Fact and Fiction
4. The Legal Status of Card Counting
Show More
Card counting has long been a topic of intrigue and controversy among casino enthusiasts, sparking debates about whether it’s a strategic skill or a questionable tactic. Popular culture often glamorizes card counting, portraying it as a genius move to outsmart the house and walk away with big winnings. However, one question lingers: is counting cards illegal?, or is it simply a clever application of math and memory? The answer isn’t as straightforward as the movies make it seem.
In this blog, we’ll explore seven essential things you need to know about card counting, breaking down the rules, debunking common myths, and shedding light on how casinos view this practice.
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1. What Is Card Counting?
Card counting is a technique used primarily in blackjack. It involves tracking the ratio of high to low cards remaining in the deck. Players who count cards assign values to each card dealt, helping them predict what cards might come next. This knowledge allows them to adjust their playing strategy and reduce the house edge.
How it works: High-value cards (like 10s and aces) tend to favour the player, while low-value cards benefit the dealer. By keeping track of which cards have been played, a skilled counter can gauge when the deck is in their favour and increase their bets accordingly.
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2. The Math Behind the Card Counting Method
Card counting is rooted in probability theory. Most counting systems assign a point value to each card.
Let's say you're playing a single-deck game. As cards are dealt, you keep a running count:
- 2, 3, 4, 5, 6 (high cards): +1
- 7, 8, 9 (low cards): 0
- 10, Jack, Queen, King, ace (neutral cards): -1
After 10 hands, your count is +6. A positive count suggests more high cards remain in the deck, signalling a good time to increase bets. This is because having more high cards in the deck improves your chances of getting a blackjack or a strong hand.
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3. Famous Card Counters: Fact and Fiction
The most well-known example of successful card counting is the MIT Blackjack Team. This group of students from MIT, Harvard, and other top universities used advanced counting techniques and team-based strategies to win millions from casinos in the 1980s and 1990s.
The team operated by dividing roles among members. Some tracked the count, while others swooped in to place large bets when conditions were favourable. Their success was so remarkable that it inspired books and movies like "Bringing Down the House" and "21." But it also led casinos to tighten their security and anti-counting measures.
Another notable figure is Tommy Hyland, a professional gambler who organized card counting teams in the 1970s. Hyland's team faced legal challenges but continued to win consistently for many years. Their success proved that card counting could be practical and sustainable as a long-term strategy.
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4. The Legal Status of Card Counting
Here's the crucial question: Is card counting illegal? The short answer is no, at least not in most places. Card counting relies on players' mental skills rather than external devices or cheating methods. Because of this, it's not considered illegal in most jurisdictions.
However, this doesn't mean casinos welcome card counters with open arms. Casinos are private businesses and can refuse service to anyone they suspect of counting cards. While you won't face criminal charges for counting cards, you might get added to The Griffin Book—a database of people who've been banned from casinos.
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5. Card Counting Around the World
The legal status of card counting varies depending on where you are. While not explicitly illegal, card counting is heavily frowned upon in the US, UK, Canada, and Singapore. Casinos can refuse service or ban players they suspect of using the technique. If you get caught in Singapore, you may even face fines.
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6. Card Counting: Fair Game or Foul Play?
The legality of card counting doesn't end the debate about whether it's right or wrong. Supporters argue that it's a legitimate skill, similar to strategy in poker or chess. They say it levels the playing field between the casino and the player, rewarding intelligence, practice, and discipline.
On the other hand, critics argue that card counting disrupts the intended balance of casino games. They see it as exploiting a loophole in a way that feels more like manipulation than skillful play. Casinos contend that this behaviour violates the principles of fair play and can lead to significant financial losses.
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7. How Casinos Fight Back Against Card Counting
Casinos take card counting seriously because it can impact their profits. When players count cards effectively, they reduce the house edge. This can lead to financial losses for the casino and damage their reputation if they're seen as "beatable."
To combat card counting, casinos employ measures like:
- Frequent shuffling: By shuffling decks more often, casinos disrupt a counter's ability to maintain an accurate count.
- Advanced surveillance: Casinos use sophisticated systems, including facial recognition and player tracking software, to identify known or suspected card counters.
- Dealer training: Casino staff are trained to spot behaviours associated with card counting, such as varying bet sizes based on the count.
- Multiple decks: Casinos often employ multiple decks of cards in games like blackjack to make card counting more difficult. Using several decks increases the complexity of tracking the ratio of high to low-value cards, posing a greater challenge for those attempting to count cards.
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So, Is Card Counting Worth the Risk?
Counting cards is not illegal, but at the end of the day, your goal should be to beat the house at blackjack. While the watchful eyes of casino security might add an extra thrill, they shouldn't impact your strategy. Focus on managing your bankroll, making smart betting decisions, and gambling responsibly. Also, remember why you stepped onto the casino floor in the first place—to play the game and potentially win.
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