Game of Life
Draw cells and watch Conway's Game of Life evolve, with a rule lens that marks which cells will be born or die next and explains why.
Game of Life
Draw cells and watch Conway's Game of Life evolve, with a rule lens that marks which cells will be born or die next and explains why.
About Game of Life
Conway's rules, made visible
Every generation, each cell counts its eight neighbours: a live cell with two or three live neighbours survives, fewer dies of loneliness, more dies of crowding, and an empty cell with exactly three is born (B3/S23). All cells update at once. With the rule lens on, the next births are marked with green dots and the next deaths with red outlines. Click a cell, or move the cursor with the arrow keys, to see its neighbour count, what happens to it next and which rule applies. The game also watches for the end: when every cell has died, when the board stops changing, or when it repeats an earlier generation, it pauses and says which one and from which generation.
Drawing, patterns and the lifespan challenge
Drag across the board to draw; starting on a live cell erases instead. Pick a pattern from the catalogue to stamp it with a click, and rotate it 90 degrees at a time. Play runs at slow, normal or fast speed, the step buttons move one generation, back undoes the last 200 generations, and rewind returns to the board as it was when you last pressed play. Edges are either solid, where everything outside the board counts as empty, or wrap-around, where the left and right and the top and bottom are joined. In the lifespan challenge you place up to 5, 8 or 12 cells, then press play and cannot edit again; it ends when the board dies out, freezes, starts repeating or reaches 3,000 generations. The result card shows how long it lasted, how it ended, the largest population and when it first hit the wall, and the best result for each cell count, board and edge setting is kept in this browser only.
FAQ
Common questions and answers about this topic.
What are Conway's Game of Life rules?
Each cell checks its eight neighbours once per generation. A live cell with fewer than two live neighbours dies from underpopulation, one with two or three survives, and one with more than three dies from overpopulation. A dead cell becomes alive when it has exactly three live neighbours. Every cell updates at the same time.
What does B3/S23 mean in the Game of Life?
B3/S23 is a compact way to write Conway's rules. B3 means a dead cell is born with exactly three live neighbours. S23 means a live cell survives with two or three live neighbours. Any other neighbour count leaves a dead cell dead or causes a live cell to die.
How do you use this Game of Life simulator?
Choose Sandbox and press Start. Drag across the board to draw cells, starting on a live cell to erase, or stamp a pattern from the catalogue, or press Random to fill about 30 percent of the board. Press play (or P) to run, use the step buttons to move one generation forward or back, and rewind to return to the board you started from. You can keep drawing or stamping while it runs; there is no need to pause first.
What does the rule lens show?
It marks every cell that will be born in the next generation with a green dot and every cell that will die with a red outline, and counts both. Click a cell or move the cursor with the arrow keys and it explains that cell: how many live neighbours it has, whether it survives, dies of loneliness or crowding, or is born, and which part of B3/S23 applies.
What is the lifespan challenge?
You get only 5, 8 or 12 cells. Place them, press play and see how many generations the pattern lasts before it dies out, freezes, starts repeating or reaches 3,000 generations. Some tiny patterns, known as methuselahs, take a very long time to settle; the R-pentomino has only five cells but needs 1,103 generations on an unlimited board. A smaller board or solid edges can cut that short.
Why is the Game of Life called a zero-player game?
You choose the starting cells, but after that the pattern evolves deterministically from the rules without turns, opponents or further decisions. That is why it is called a zero-player game. You can still pause this simulator, edit cells and start again to explore a different initial pattern.
What happens to cells at the edge of this grid?
You choose in the lobby. With solid edges, everything outside the board counts as empty, so patterns that reach the border change or break up; a glider hitting a wall usually turns into a still block. With wrap-around edges, the left edge joins the right and the top joins the bottom, so a glider leaves one side and comes back on the other. Neither is the same as the unlimited grid of the theory, so long-lived patterns may end sooner here.
Which classic Game of Life patterns can you try?
Open the catalogue: still lifes such as the block and beehive never change, oscillators such as the blinker, toad and pulsar repeat every two or three generations, spaceships such as the glider and lightweight spaceship travel across the board, methuselahs such as the R-pentomino, diehard and acorn grow for a long time from a few cells, and the Gosper glider gun fires a new glider every 30 generations. Pick one, click to stamp it and rotate it as you like; the gun needs the 48 by 48 board.