No real-money wagering
Bankrolls, bets, and P&L inside Stack21 are simulated. No real money changes hands. Stack21 does not facilitate gambling and is not a real-money operator.
Stack21 is a training simulator.
Stack21 exists to help people learn blackjack and Hi-Lo card counting in a risk-free environment. It is not a casino, not a gambling product, and not a tool designed to be used while you are playing live.
Not for use while playing live
Stack21 is built to be used at home, the way a pianist practices on a keyboard before a recital. Running an app on the floor is against the rules of every casino in every jurisdiction we know of.
We do not support, encourage, or build features for in-casino use. Do not use Stack21 on the floor.
Card counting is not illegal
Counting cards in your head, using only information available to every player at the table, is legal in every US jurisdiction we are aware of. Casinos are private businesses though, so they can refuse service or ask counters to leave. Knowing the rules of the venue you walk into is on you.
Problem gambling resources
If gambling is causing problems in your life or in the life of someone you know, help is available.
- United States, National Problem Gambling Helpline. 1-800-522-4700. 24/7, confidential, free.
- US text line. Text 800GAM to 800-522-4700.
- United Kingdom, GamCare. gamcare.org.uk. 0808 8020 133.
- Australia, Gambling Help Online. gamblinghelponline.org.au. 1800 858 858.
- Canada, ConnexOntario. 1-866-531-2600.
Self-exclusion and account deletion
If you no longer want access to Stack21, delete your account at any time from the billing portal or by emailing hello@stack21.app. Deletion is irreversible.
Stack21 makes no claim that using the app will make you profitable at a casino. Card counting reduces the house edge under specific game conditions but does not guarantee a positive expected value. Anyone telling you otherwise is selling something.