Play lower numbers onto opposite colors (reds on blacks and blacks on reds)
If you have a King, you MAY play it on one of the four corner areas, which then becomes a new pile to play lower numbers of opposite colors onto.
You may move an entire pile onto another pile if the base card of the moved card is lower and opposite to the top card of the destination pile
If an orthogonal pile is empty, you may play any card onto it
If you can't do any of the above, draw a card and pass
First player to get rid of all their cards wins the round
Kings score -10 per each, other cards score -1 per each