Cellular automata, played and explained

Four rules.
No players.
A whole universe.

In 1970 John Conway defined a game with no winner, no strategy and no moves. Fifty years later people are still finding new things inside it - including a working computer. Start it up and see for yourself.

Open the Lab Learn the rules
Running rule B3/S23 — born on three, survives on two or three
1970 first published in Scientific American 2 states per cell 8 neighbours Turing complete since 1982 5 cells in a glider ∞ patterns still undiscovered

The premise

A grid decides its own future, one generation at a time.

Every cell looks at its eight neighbours and applies the same four rules. Nobody is steering. Everything you see - the gliders, the guns, the cathedrals of debris - is a consequence of arithmetic done in parallel, everywhere, forever.

  • UnderpopulationA live cell with fewer than two live neighbours dies.
  • SurvivalWith two or three, it lives on into the next generation.
  • OvercrowdingWith more than three, it dies.
  • ReproductionA dead cell with exactly three live neighbours comes to life.
Walk through a generation
gosper glider gun — B3/S23

Bill Gosper's glider gun, 1970. It fires a glider every thirtieth generation and never stops — the discovery that proved Life can grow without limit.

Where to start

Four ways in

Whether you want to play with it, understand it, or argue about what it means.

01

The Lab

Draw cells, stamp classic patterns, change the rule and watch the population curve. Full zoom, pan and share links.

Start simulating
02

The encyclopaedia

Still lifes, oscillators, spaceships, guns and methuselahs - the whole taxonomy, each one running live on the page.

Browse patterns
03

The wider field

Von Neumann's self-replicating machine, Wolfram's 256 rules, and the proof that a one-dimensional automaton can compute anything.

Read the theory
04

What it means

Emergence, undecidability, digital physics and the uncomfortable question of whether the universe is doing the same thing.

Follow the argument

Specimens

The patterns that made it famous

Every tile below is a real simulation running in your browser, not a video.

Open the gallery

Beyond Life

Life is one rule out of billions.

Change a single digit and you get a maze generator, a replicator, or a world where nothing ever dies. Step outside the square grid entirely and you get ants that build highways, wires that carry electrons, and continuous automata that look disconcertingly like microorganisms.

Explore the Labs Read about variants

Elementary automata

256 rules on a single line of cells. Rule 30 is chaos; Rule 110 is a computer.

Langton's Ant

Two rules, 10,000 generations of mess, then a perfectly straight road.

Brian's Brain

Three states, a refractory period, and almost nothing that stands still.

WireWorld

Copper, electron heads and tails. Enough to build logic gates.

Your move

Nothing here is a recording.

Open the Lab, click a few cells, and press play. Whatever happens next has probably never happened before.

Open the Lab