Three tiny rules, no designer, and yet gliders, blinkers and whole ecosystems appear. Click cells to seed life, then watch a universe build itself from nothing.
Each cell is alive or dead. Next generation: a live cell with 2 or 3 neighbours survives; a live cell with any other count dies; a dead cell with exactly 3 neighbours becomes alive. That's the whole rulebook — and it's a Turing-complete machine: the glider you can place travels forever, and patterns can compute anything.