Throw 3 darts on each treble from 20 to 1.
You need to hit at least 1 dart on the treble to move on to next treble.
If you hit 2 or 3 darts on the treble the treble is locked and the next treble is now your new starting treble.
If you fail to hit the treble with your 3 darts you need to start over on your starting treble.
Click on the buttons or use the keypad numbers 0, 1, 2 and 3 to track your progress.