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Play starts the simulation. The field is a fixed petri dish: nothing scrolls — the culture of live cells grows, spreads, and competes in place like a living organism (the default "Organism" rule grows dense coral-like colonies). Drop anything anywhere inside the dish. Switch Mode to 1D scroll for the classic elementary-automaton waterfall view, or Dish shape to Rectangle for a full-frame field. Tap or drag on the field to paint life cells. Drag tiles from the palette onto the field: Poison Pills ☠️ randomly kill nearby cells for a random time, Super Cells ⚡ force nearby cells to live for a random time, and Rocks 🪨 build a permanent walled boundary whose inside stays lifeless until enough live cells (default 4) touch the outside of its walls — then it unlocks for good. On phones the dragged object floats above your finger so you can see where it will land, and the page will not scroll while you drag. Easier on small screens: tap a tile once to arm it (it highlights green), then tap the field where you want it placed. Change any setting below the field, then press ✔ Activate settings to apply. 📸 Capture downloads the current design as a reproducible JSON layout and a PNG image (they go to your browser's Downloads; on phones, long-press the preview to save to Photos). Load restores a saved JSON layout exactly.
A one-dimensional cellular automaton (Stephen Wolfram's "elementary rules") drawn as a space-time diagram. Each cell looks at itself and its two neighbors; the 8 possible patterns map to the bits of a rule number 0–255. Rule 30 is famously chaotic (it was used as a random number generator), Rule 90 draws Sierpinski triangles, Rule 110 is proven Turing-complete, and Rule 184 models traffic flow. The 2D presets run John Conway's Game of Life (birth on 3 neighbors, survival on 2–3) and its variants HighLife and Seeds.
Poison Pill: every generation, each cell within its kill radius has an independent probability of dying. Super Cell: every generation, all cells within its force radius are set alive, overriding the rule. Rock: its outline is wall (never alive, counts as a dead neighbor, blocks birth across it); its interior is forced dead until the unlock threshold of live cells touches the outside of the wall, after which the interior follows normal rules forever. Hibernation is a third cell state: a dying cell whose neighbor count matches the Hibernate set sleeps for N generations (counting as dead), then wakes alive.
Capture writes {v, name, settings, gen, cells:[[row,col,state,timer]…], objects:[…]}.
state is 1 alive or 3 hibernating; objects carry
{type, col, row, w, h, ttl, unlocked}. Any layout can be written by hand and loaded.
Brian's Brain (3-state automaton) · Wireworld circuits · Langton's Ant · Larger-than-Life and continuous rules (Lenia) · importing rule tables from text · generating sound from the live row · GIF export of a whole run · a library of gliders and spaceships · shared multiplayer fields · evolutionary search for interesting rules.
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