PETRI SIEGE

Rule B3/S23 · Immigration variant · 1v1 real time

PETRI
SIEGE

Two strains of cellular life share one dish. Seed Conway patterns in real time, hold the wells that feed you, and push your cells through the enemy membrane before theirs reach yours.

Play nowHow it works

How it works

Four rules. Everything else is Conway.

Seed
Spend energy to drop patterns into your territory. From then on every cell obeys Conway: it survives with 2 or 3 neighbours and is born with exactly 3.
Convert
A newborn cell takes the colour held by the majority of its three parents. When strains collide, the wreckage belongs to whoever outnumbers the other.
Claim
Cells near a well swing it toward your strain. Each well you hold adds +1.6 energy/s and feeds a radius around it. Settled structures outside fed ground starve after 12 seconds.
Breach
Each enemy cell that touches your membrane costs your nucleus 1 point, and enemy cells loose in your territory drain it slowly. Each nucleus holds 100. At 4:00 the dish overgrows: income doubles and damage keeps climbing.

The deck

Seven ways to change the dish

  • Bulwark

    6 energy

    Block, still life

    A cheap 2×2 wall that soaks up gliders and anchors a captured well.

  • Glider

    12 energy

    Glider, c/4 diagonal

    Travels diagonally and wraps top to bottom until it hits something. Follow the dotted path.

  • Lancer

    26 energy

    Lightweight spaceship, c/2

    Twice as fast as a glider and flies straight. Nine cells of damage if it arrives intact.

  • Eater

    18 energy

    Eater 1, still life

    Digests gliders that strike its hook and survives the meal. Rotate it to face the stream.

  • Bloom

    34 energy

    R-pentomino, methuselah

    Five cells that erupt into chaos for over a thousand generations. Seed it at the front line.

  • Hive Gun

    140 energy

    Gosper glider gun, p30

    A factory that fires a glider every 30 generations until something breaks it.

  • Purge

    45 energy

    Ability, radius 5

    Sterilises a circle inside your territory. Every cell dies, yours included.

Ways to play

Against the machine, the couch, or the world

  • Versus AI

    Three difficulty levels. Hard plays faster, builds Hive Guns early and earns a little extra energy.

  • Local 2-player

    One screen, two strains. Tap inside your own territory, or split a keyboard: WASD against the arrow keys.

  • Online

    Host a match and send the five-letter code. Seeds land 0.7 s after the click so both dishes stay identical.

Open the dish