Chipfire

A turn-based board game of strategy for 2–4 people. Plays in the browser, nothing to install.

Add orbs until a cell is full, and it detonates into its neighbours — every cell the blast touches changes hands. One move can flip territory you never touched.

Before
Two generations in
After
Orange adds one orb to a middle cell already holding 3. A middle cell has 4 neighbours, so its limit is 4 — it is now full, and it fires. Its neighbours fill in turn, and theirs after that: four generations, five explosions. Blue is left with one cell.

There are only three rules

  1. 1Place one orb in an empty cell or one you already own.
  2. 2A cell is full when it holds as many orbs as it has neighbours — 2 in corners, 3 on edges, 4 in the middle — then it explodes into all of them.
  3. 3Every cell the blast reaches becomes yours, and may explode in turn. You win when every orb on the board is yours.
The identity elementThis picture was not drawn. It was computed, by exactly the toppling rule the game runs on. It is the identity element of the abelian sandpile: the one configuration that, added to any other, changes nothing. Four heights, 0 to 3.The classical model (Dhar 1990, on Bak–Tang–Wiesenfeld 1987) lets orbs fall off the edge and topples every cell at four. Chipfire’s board loses nothing and takes its threshold from the neighbour count — 2 in corners, 3 on edges. So this is the game’s ancestor, not a portrait of its board.

Other ways to play

  • PuzzlesTwelve boards, one winning move on each.
  • VersusTwo devices, a direct browser-to-browser connection.
  • ReplayLoad a game code and step through it move by move.