CELLULAR AUTOMATA LAB
Any rule of the form B3/S23: which neighbour counts make a cell appear, and which let it live. Change two digits and Life becomes a maze generator, a crystal, or something that eats itself.
Drag on the grid to draw, hold Shift (or use the right button) to erase. Drawing while it runs is allowed — that is half the fun.
The interchange format every Life catalogue uses: run-lengths of b dead and
o alive, $ for end of row, ! for end of pattern. Paste
anything from a pattern collection in here, or copy what you built out.
Every rule here is a two-state, 8-neighbour (Moore) outer-totalistic rule, which is the family Conway's Life belongs to. A repeat of an earlier generation is detected by hashing each state, so a still life, a blinker or a period-15 oscillator names itself once it settles — a pattern that never repeats simply never triggers it.
"Four rules, no randomness, and nobody can tell you what happens on turn 10,000 without running it."