Introduction

Pilo is a finite territory game for two players: Blue and Orange. It is played on the spaces (squares) of an initially empty square board. The recommended board sizes are between 6x6 and 10x10 squares.

Both players must have access to a sufficient number of disks of their own color and a sufficient number of neutral blocks.

Definitions

A stack is a disk lying directly on the board along with all other disks piled onto it on the same square.

The height of a stack is the number of disks in it.

A group is a stack along with all other like-colored stacks one could reach from it through a series of steps between orthogonally adjacent stacks of its color.

Similarly, a patch is a square not occupied by a block along with all other such squares one could reach from it through a series of steps between orthogonally adjacent squares not occupied by blocks. Note a patch may contain any number of groups, as well as empty squares.

The size of a group or patch is the number of squares it spans.

Play

Blue plays first, then turns alternate. On your turn, if possible, make exactly one of these board plays:

- Place a disk of your color on an empty square.

- Move a stack of your color any number of squares in a straight orthogonal line, without jumping over any blocks or enemy stacks, to a square occupied by an enemy stack of the same height. Then, remove this enemy stack, add a disk to your stack on that square and place a block on the square from which you just moved your stack. Note a stack can jump over friendly stacks.

If you have no board plays available on your turn, you must pass. Passing is otherwise not allowed.

The game ends when both players pass in succession. Then, for each patch on the board, the players jointly remove pairs of opposite-colored groups of the same size from it until there are no more such pairs to remove. The player with the biggest group left over in a patch owns the patch. Empty patches are owned by neither player.

The player with the higher score in the resulting position wins. Your score is the sum of the sizes of the patches that you own. If there is a tie, whoever made the last board play loses.

Pie rule

The pie rule is used in order to make the game fair. This means Orange will have the option, on their first turn only, to swap sides with their opponent instead of making a regular move.