The maths behind Dobble

A picture of the card game Dobble.

In this series I will guide you through my journey in re-creating an online version of Dobble, or Spot It, depending on where you’re from, the fast-paced, observational game pushing stress levels to breaking point and ruining friendships all in the name of fun since 2009. I will break this project into several parts, starting with a peek into the theory and mathematics behind the game’s principles and how we can create our own deck of cards, and then follow up with a walk through the implementation on how I created my very own multiplayer Dobble game using JavaScript. My hope is that by the end of these articles you’ll have a better understanding of the theory behind how the game works and the know-how to go off and create your very own online version of Dobble.

The brains behind the game

Before I get started on nose-diving into the nitty-gritty mathematical principles hidden behind the glamorous face of the game, let’s begin by clarifying how the game is played and the fundamentals behind it’s structure.

The concept of Dobble is, in theory, very simple.

1. Each deck is made up of 55 cards.
2. Each card has 8, different symbols on it.
3. Any two cards have exactly one matching symbol between them.