In the tactical tile-laying game Reef, players are creating colourful coral reefs by stacking playing pieces onto their tableau. How the reef grows is determined by cards with a double function: playing a card means you can first place new coral stones of the displayed colour onto your reef. Directly afterwards scoring takes place, based on the coral colour and shape depicted on the card. The clever twist is that the scoring part of the card never matches the colour of the coral it lets you place. That’s why the most successful reef builders are those players who are able to get a good combination of cards from the communal display and play these in the right combination over several turns. It’s a tricky task, whose simple rules show remarkable depth.