First you have to place your bet. If you win you'll recover two times more money but If you lose you'll lose all bet. When you place bet click Deal. Then you will get two cards. On the right you'll see amount of your cards. You should get 21. You can have less than 21 but musn't have more than 21 or you'll bust and lose. Ace can be 1 or 11. Just click on it to change its amount. To take one more card click Hit. Be carefull because you can bust!!! When you don't want to get more cards click Stand. Then dealer will start taking his cards. If he bust you win. If his cards have bigger amount than you he wins and you lose your bet. If his amount is the same like yours you draw and get your money back. But if your cards have bigger amount than his you will get your bet twice!!!
Please tell in comments any problems. I'm sorry for my bad English, I'm still learning. :-)
