Game of Life is played on a grid of square cells - like a chess board but extending infinitely in every direction. A cell can be live or dead.
- A live cell is shown by putting a marker on its square.
- A dead cell is shown by leaving the square empty.
- Each cell in the grid has a neighbourhood consisting of the eight cells in every direction including diagonals.
- To apply one step of the rules, we count the number of live neighbours for each cell. What happens next depends on this number.
- A dead cell with exactly three live neighbours becomes a live cell (birth).
- A live cell with two or three live neighbours stays alive (survival).
- In all other cases, a cell dies or remains dead (overcrowding or loneliness).
Note: The number of live neighbours is always based on the cells before the rule was applied. In other words, we must first find all of the cells that change before changing any of them.