The object of Regata 21 is to stack cards in groups that add up to 21. Click
the Hit buttons or lanes to stack your cards in each of the 4 lanes. Each
stack is a separate hand, and you can play several hands at once. The cards
will clear off when you WIN (get a 21 or “5-card Gimmie”) or BUST (go over 21).

If you can’t stack a card without going over 21, choose a lane that you want
to clear. Again, click the HIT button or lane. You will BUST and lose scores,
but the lane will be clear for you to stack more cards. For maximum awards,
play all 52 cards before the time runs out.