Rule 30 grows a whole universe from a single black cell, and it has 255 siblings. Here is the whole family of 256 to play with.

One Black CellGrow a tiny universe from eight small laws

Every row, each cell looks at itself and its two neighbours, and one of eight laws says whether it is black below. Pick the laws by number, from your birthday or by hand, start from one black cell or your name, and the page sews 64 rows into a quilt. Then say what you wish it did - one run tells you if it is already there, one flip away or needs more than one flip.

Try a sample:

1 The laws

A rule number From a birthday

Rule (0 to 255)

Nudge

Each card: the three cells on a row (left, centre, right), and below them the cell they make. Press a card to flip that law.

Start from Name

2 The quilt free

The page's estimate: -

32 rows 64 rows

The eight flips

What you get by flipping each law on its own - same seed, 64 rows, the page's estimate.

Law	Rule	Behaviour	Black	Try

3 Your wish

What do you wish this universe did? (calmer, wilder, more triangles, shapes that travel...)

Free check - is a behaviour here or one flip away?

One run reads the facts above, turns your wish into one of the five behaviours, and applies a fixed rule: already there if the estimate matches, one flip away if one of the eight flips does, otherwise no single flip. It names the law to flip and writes a short field guide with things to look for.

Pricing as soon as the session is ready...

The reply, as it came

4 Saved universes

How the free side works

The page runs the universe for 64 rows on a strip wide enough that the pattern never reaches its edge, so it behaves like an endless row. Its estimate checks, in order: does every row go flat (fades); is the rule one of the six documented complex ones - 54, 110 and their twins (lives on the edge); from one black cell, does the pattern pinch back to a few cells at rows 8, 16 and 32 (nests); do rows 40 to 63 repeat with a period of up to 12 rows, still or sliding (repeats); otherwise churns. It is an estimate from 64 rows, not a proof.

A name is spelled letter by letter in five bits (A = 00001, B = 00010 ... Z = 11010), up to 12 letters. A birthday rule is the day of the year (1 January = 1, counted in a non-leap year, so 29 February shares 1 March's day), counted from 0 again after 255: day 296 is rule 40.

The run gets these facts and the eight flips, and the page checks every reply: the verdict follows the rule for the behaviour it read in your wish, the named flip really gives that behaviour (and is the closest in density), every thing to look for points to a real fact, every number in the prose is one the page supplied, and the word limits hold.