The universe is an infinite grid of square cells. Each cell is either alive (white) or dead (black). Every cell has eight neighbours (horizontal, vertical, diagonal).
At each tick, every cell updates simultaneously according to these rules:
- Underpopulation. A live cell with fewer than 2 live neighbours dies.
The highlighted live cell has only 1 alive neighbour → next tick it dies. - Survival. A live cell with 2 or 3 live neighbours stays alive.
Part of a 2×2 block: the highlighted cell has 3 alive neighbours → it survives (the whole block is stable). - Overpopulation. A live cell with more than 3 live neighbours dies.
The highlighted cell has 5 alive neighbours → next tick it dies. - Reproduction. A dead cell with exactly 3 live neighbours becomes alive.
The highlighted dead cell has exactly 3 alive neighbours → next tick it is born.
In short: B3/S23 — a cell is born with exactly 3 neighbours and survives with 2 or 3.
Tips
- Try loading the Glider from the library and watch it travel diagonally.
- The Gosper glider gun keeps producing gliders forever.
- Use the code panel to script patterns programmatically.