The long version
How it works
Color Wars is a chain-reaction game. It takes about ten seconds to learn and considerably longer to stop losing at.
Opening
Your first move of the game is different from every move after it. You drop a cell of three orbs onto any empty square you like. That is the only time you ever place on empty ground.
An opening cell sits on all three orbs wherever you put it, corner and edge included. It ignores the usual limit exactly once: only when a fourth orb arrives does it go off, and from then on it is an ordinary cell again.
Where you put it matters more than it looks, because a cell only ever sheds into the squares it touches edge-to-edge. Open in the middle and your three orbs spill four ways. Open in a corner and they have two ways out - and both of those squares sit next to the diagonal, so an opponent who opens there can take the pair in a single move. Corners are a trap on move one.
A turn
After the opening you add one orb per turn, and only ever to a cell that is already yours. You cannot claim an empty square and you cannot touch theirs, so the only way to gain ground is to burst into it. Then the other player goes.
Capacity
Every cell can hold one orb fewer than it has neighbours touching it edge-to-edge. Corner cells have two neighbours, so they hold one. Edge cells hold two. Cells in the middle hold three. The moment a cell would hold more than that, it bursts: it empties completely and sends one orb into each neighbour.
Capture
Anything an orb lands on becomes yours - the pile that was already sitting there included. A single burst can convert four cells at once, and if any of those were already close to full, they burst too. That is the whole appeal. A quiet board can turn over completely in one move.
Winning
Once both players have had a turn, whoever is left holding no orbs at all has lost. Nothing else ends the game - there are no draws and no move limit.
Three things that took us far too long to learn
- Corners are cheap to hold, terrible to open on. Once the game is running they take a single orb and can only be attacked from two sides. On move one they are the worst square on the board.
- Open in the middle. Three orbs with four ways out beats three orbs with two.
- Never park a loaded cell next to their loaded cell. Whoever moves first takes the whole exchange.
- Being behind is fine. Material means almost nothing here; one well-placed orb can take half the board.