INTRODUCTION

Rumbo is a territory game for two players: Vertical and Horizontal. It's played on the intersections (points) of an initially empty square board. Both players must have access to a sufficient number of stones in two colors.

The four orthogonal adjacencies of a point are named after the cardinal points. Vertical owns the north and south adjacency directions, the pairs north-east and south-west and the triplets north-south-east and north-south-west; Horizontal owns the east and west adjacency directions, the pairs north-west and south-east and the triplets east-west-north and east-west-south.

DEFINITIONS

In these rules, ''adjacent'' always means ''orthogonally adjacent''. A group is a maximal set of like-colored, mutually adjacent stones. A liberty of a group is an empty point adjacent to it. A hole is an empty point such that all points adjacent to it are occupied by stones of the same color. To claim a group is to mark it as yours.

PLAY

Vertical plays first, then turns alternate. On their turn, a player must place one stone of any color on an empty point where it doesn't create any holes. Then, each unclaimed group without liberties is claimed by the player who owns the set of adjacencies of stones in that group to the first stone placed on that turn. The game ends when the board is full. A player's score is the total number of stones in the groups that they have claimed. The player with the highest score wins.