Play matching cards on your pile while avoiding giving points to other players.
Game play in Heul doch! Mau Mau is simple, but it may bring you to tears all the same when you give points away to other players.
The game consists of 98 cards, with 1-7 each appearing twice in seven colors. Each player starts with a random card face up in front of them as a personal discard pile as well as a hand of four cards. On a turn, you must play one card from your hand following the familiar game play rules of matching the color or number. Ideally you want to play on your own pile, but if the card you would play matches the top card of your left- or right-hand neighbor's discard pile, then you must play it there instead!
Maybe you can choose a card in hand that matches only your top card? If you have no valid play or don't want to give points away to someone else, you can play the card face down on your stack, showing the weepy onion on the card back. On your next turn, you can play any card you like on your pile — except if it matches a neighbor's top card, of course, in which case you must give it away. (You can't play on a neighbor's onion card.)
Once all the cards have been played, everyone scores for the cards in their pile — but first they must count the number of onion cards in their pile. However many onions they have, they must remove all matching number cards prior to scoring. If you have four onions, for example, you must discard all 4s — and this is bad since all cards score points equal to their value. If you have ten onions, then you first discard all 7s, then all 3s. Whoever has the most points wins!
Heul doch! Mau Mau includes twelve special action cards that can be used to twist up game play when played instead of a number card: