The worst thing that could happen is that a casino might ban you from their premises or restrict your play in Blackjack. Yet, you will never face any legal consequences.
You probably have heard of card counting. Hollywood movies like ‘21’ and numerous YouTube interviews from gamblers who have beaten casinos claim that card counting is the best way to win. Yet, because card counters are often thrown out of casinos, a lot of people question their legality. Let’s try to understand what the reality is like in the UK – is card counting illegal?
The term “card counting” is often shrouded in mystery. It’s a mental tactic when players keep track of the ratio of both high and low cards in the deck. This helps understand whether the odds are in their or the house’s favour.
One of the most beginner-friendly card-counting methods is the so-called Hi-Lo system. In this system, cards are assigned a value number. It’s +1 for low cards (2-6), 0 for neutral cards (7-9) and -1 for high cards (10-A).
When the game is going on, and the cards are dealt, players need to keep a running count in their minds by adding or subtracting points. If Blackjack is played with a shoe (multiple decks), the running count needs to be converted into a true count by dividing it by the number of probable decks remaining.
Generally, the higher the cards left, the better the player’s chances. Refer to the table below to better understand how the Hi-Lo legal card counting system works
| Card Rank | Running Count Adjustment | Odds of the player |
| 2 | +1 | Improve |
| 3 | +1 | Improve |
| 4 | +1 | Improve |
| 5 | +1 | Improve |
| 6 | +1 | Improve |
| 7 | 0 | No change |
| 8 | 0 | No change |
| 9 | 0 | No change |
| 10 (10, J, Q, K) | -1 | Decrease |
| Ace | -1 | Decrease |
Opposite to what you might believe, card counting is all mental calculations. Players can count cards without using any cheat devices or manipulating the table. Yet the fully legal status of card counting in the UK doesn’t mean that casinos like it. Gambling establishments discourage players from using it, and once a card counter is spotted, they are often asked to leave.
Because casinos openly show how much they dislike and how far out of their way security goes to bar card counters from play, people think it’s illegal. However, counting cards is absolutely, 100% legal in the UK and elsewhere around the world.
Even though card counters are able to establish a clear advantage over the house, what they do isn’t against the law in the UK. The Gambling Act 2005 governs all gambling activities. While it criminalises cheating and collusion, card counting is legal in the UK if performed mentally, without any external aid.
Please refer to this table for further clarification of what’s considered legal and illegal in the UK, surrounding card counting.
| Action | Legal Status in the UK | Notes |
| Mental card counting | ✅ Legal | Using one’s memory and calculation skills without any supportive devices |
| Using devices to aid counting | ❌ Illegal | Prohibited under the Gambling Act 2005 |
| Collusion with other players | ❌ Illegal | Considered cheating and is a criminal offence |
| Edge sorting (e.g., Phil Ivey case which we cover later in the guide) | ❌ Deemed cheating | Ruled as cheating in UK courts, leading to forfeiture of winning |
Even if counting cards at a Blackjack table is legal, this doesn’t prevent a casino (a private establishment) from refusing service. If a player is suspected of counting cards, the casino may refuse to accept their bets, ask them to leave immediately, or even ban them from the premises.
Once again, under the Gambling Act 2005, card counting is not illegal in the UK if a player is tracking the cards mentally. However, since casinos hate card counting, they do use some countermeasures to fight against it.
In order to protect their interests and the business, casinos utilise a handful of tricks and operational strategies against card counters. These include but aren’t limited to:
Under Section 42 of the Gambling Act 2005, it is only an offence if a player cheats or assists another person in doing so. Since Card Counting is a mental skill, it’s not an offence.
However, if you receive help from the outside, the casino has the right to not only ban you but to also initiate legal action. So, card counting is legal under the Gambling Act 2005 if you do it yourself.
All of these measures make card counting a lot more challenging to execute. However, if a casino doesn’t have a lot of advanced countermeasures, skilled players are able to take advantage of the less stringent surveillance and get ahead.
There’s often a debate in the world of gambling which centres around the need to distinguish skill from cheating. Card counting vs edge sorting is a very polarising topic in this field.
Card counting is a Blackjack strategy that’s been around for a while and isn’t considered cheating. The success of this strategy relies on the ability of the player to keep an accurate count in their head. Since it relies on memory and skill, not game manipulation, almost everyone accepts it as a legitimate strategy, even though casinos dislike it.
On the other hand, there are many tricks and tactics that could be labelled as similar but fall under the ‘cheating’ umbrella. One such tactic is called edge sorting. It involves spotting tiny flaws on the backs of the cards to identify their values. Edge sorting also relies on dealer habits and spotting or even interfering with other imperfections in the gameplay. So, whereas card counting isn’t illegal in the UK, edge sorting has been proven to be illegal, not just by casinos but also by court rulings.
In 2012, one of the top poker players in the world, Phil Ivey, fell into an expensive legal battle against UK casinos. The poker legend was playing Punto Banco baccarat at Crockfords Club and was winning big. After the game in question, Ivey was set to receive £7.7m. However, the winnings were never wired to the American; only his initial £1m stake was returned.
After a lengthy legal battle, UK justices upheld the previous decision on the basis that the player was knowingly dishonest. To sum up, counting cards is not and cannot be illegal, while other tactics may cross the boundary. Players need to be mindful of the risks associated with what happens if they’re caught counting cards or edge sorting.
The worst thing that could happen is that a casino might ban you from their premises or restrict your play in Blackjack. Yet, you will never face any legal consequences.
Card counting cannot guarantee a profit, as it only shifts the odds in favour of the player over a long period. Variance is still a factor and can lead to losses.
Always keep a cool head, don’t argue or fight and politely leave to avoid any kind of escalation. Demand that your winnings are cashed out and have a backup casino ready to continue your game.
Not necessarily. Some casinos have stricter internal policies and might restrict your bets or prevent you from playing while others may allow you to keep going. However, if you count cards, always have a backup casino you can switch to, after you get restricted or banned.
Yes, it is possible to count cards online but the nature of these games makes it a lot more difficult to obtain an edge. Since there are more decks in play and a CSM, card counting remains possible but very difficult.
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