The King is dead! With no obvious heir, the King's once-loyal commanders immediately start squabbling for control over the rich royal lands and, ultimately, the kingdom. Two contenders have emerged: you, controlling the blue faction, and your rival, controlling the pink faction. Your sages assure you that, having seized the initiative, you are sure to emerge victorious with careful strategy.

Rules

Tetro Domain is a minimalist strategy game. You and your opponent take turns claiming territories within the royal lands. On each turn you may claim a vacant territory adjacent to either the central castle or to a territory you have already claimed. You may not claim a territory already claimed by your opponent. Any territory completely enclosed by your claimed territories is also immediately claimed for you.

Some territories contain mines with a value ranging from 1 to 3. The game ends once one player controls a majority of the total value of the mines; that player is declared the winner. (Controlling the wealth of the mines ensures that their ultimate bid for the whole kingdom will be successful.)

Some tiles may also contain mountains, which are impassible and cannot be claimed by either player.

Interface

Use the arrow keys (or the mobile interface's D-pad) to navigate, the Z key (O button on mobile) to confirm, and the X key (X button on mobile) to cancel.

Pressing "confirm" on a square in the game board will claim the territory it belongs to (if that territory is eligible to be claimed). Pressing "cancel" within the game screen will bring up a pop-up menu.

Along the top of the game screen is a score track consisting of one pip for each point of value available on the board. These pips will light up in the player colors as mines are claimed, left-to-right for you and right-to-left for your opponent. The large box in the center of the score track represents the last point that is required to win the game; the number inside it shows the score that must be achieved in order to win.

Mathematical Note

From a mathematical perspective, Tetro Domain is designed around the idea of the strategy-stealing argument. This argument proves that the first player has a winning strategy, but it does so nonconstructively: it does not provide any indication of what that winning strategy might be.

Mobile Compatibility Note

This game should largely be playable on mobile devices using the onscreen PICO-8 controls. However, the functionality to copy and paste map seeds is likely not to work on mobile devices.