This activity is a game similar to the card game known as Dobble or Spot It!.

It uses a set of cards, each showing some number of symbols. Overall, there are as many symbols as cards, and each card has the same number of symbols. They key feature is that for any chosen pair of cards, there will be exactly one symbol in common, and the game is essentially a competition to find that common symbol.

It can be surprisingly difficult.

After playing, you can explore the fascinating mathematics that underlies this game via the interactive Mathematics of Dobble activity.

Intersection Detection
Find the common symbol as fast as you can
Look at the top card, then find on the matching symbol on your own card. If you have a touch screen, tap the matching symbol. If you are using a mouse, whoever is first to call out the matching symbol gets to click and check. Don't get it wrong or you'll cop a 3 second penalty!

Choose the number of symbols per card, and click Start when ready.

Player 1


Player 2