Dobble

[4] In 1976, inspired by Kirkman's schoolgirl problem, French mathematics enthusiast Jacques Cottereau devised a game consisting of a set of 31 cards each with six images of insects, with exactly one image shared between each pair of them.

[5] Dobble was released in France in 2009, and in the UK and North America in 2011 under Blue Orange Games.

In 2015, the French board game company Asmodee acquired the rights to Dobble and Spot It!

The game of Dobble with 8 symbols on each card corresponds to the finite projective plane of order 7, where each line joins 8 points.

This results in a structure with 57 lines and 57 points (72+7+1=82−8+1=57),[8] corresponding to a maximum of 57 cards and 57 symbols.

2 points on each line, 2 lines on each point
The Fano Plane
Graph of the projective plane of order 7, having 57 points, 57 lines, 8 points on each line and 8 lines passing through each point, where each point is denoted by a rounded rectangle and each line by a combination of letter and number. Only lines with letter A and H are drawn. In the Dobble or Spot It! game, two points are removed. In the SVG file, hover over a line to highlight it.