To win at Keno, you have to correctly guess the numbers that will be called during a game. You can pick 5, 10, 15, or 20 numbers out of the 20 total will will be called. The ratio of your win will change depending on the number that you can correctly call. For example, betting €5 for 5 maximum picks means that if you choose 3, you will get x3 of your bet totally €15 in winnings.