This information should be added on your main page, it is an important thing to be informed publicly in your site. However 10% seems to be too much. Lets say someone play 1BNB, if he win then he will receive 1.8BNB only? One more thing, I think you should add the option for players to set their own bet amount. With the available fixed bet amount you provide, it will not attract players to play as they can bet as what they wish.