Conway's Game of Life is a cellular automaton that is played on a 2D square grid. Each cell on the grid can be either alive or dead, and they evolve according to the following rules:
Any live cell with fewer than two live neighbors dies. Any live cell with more than three live neighbors dies. Any live cell with two or three live neighbors lives, unchanged, to the next generation. Any dead cell with exactly three live neighbors comes to life.
The complexity it creates has all sorts of cool philosophical implications. ...except my version puts this mathematician/philosopher's thought tool in the style of the Milton Bradley board game...because why not?