I use a deck that I created where each shape has a number inside and a different color. I use these cards for more than this game but that's another post. This deck has 25 cards: 5 shapes, 5 numbers, and 5 colors. I'll put out 3 or 4 decks to keep the game interesting. The best part of using a deck like this is it makes it ridiculously easy to start a new game. Each team just spreads their cards back into the playing area. If they're thinking, they're trying to remember where cards are being placed. BUT you can keep them on their toes. Maybe in Round 1, each team was searching for a shape. Now, in Round 2, they need to find a specific number.