Implo (2011)

Introduction

Implo is an original territory game for two players: Black and White. It is played on the intersections of an odd-sized square board, which is initially empty. The suggested size is between 7x7 and 11x11. There are two kinds of stones of each color: pawns and kings. The goal of the game is to end up with the most kings on the board. Draws and cycles are not possible in this game.

Definitions

In this rules, "adjacent" always means "orthogonally adjacent". A group is a set of like-colored, adjacent stones. A dead group is a group of pawns with no empty intersections adjacent to it. A dead pawn is a pawn in a dead group.

Play

Starting with Black, players take turns placing one pawn of their color on an empty intersection. Then, all the pawns on the board which belong to groups containing one or more kings become kings of the same color. This is called promoting.
If there are no dead groups at this moment, the turn ends. If there are any dead groups:

1. All the enemy dead pawns become kings of the player's color. This is called flipping.
2. All the player's groups of pawns adjacent to the flipped enemy groups are removed from the board, after which the turn ends.

It is illegal to place a pawn on an intersection where it is dead, unless it causes a flip.
The game ends when the board is full. Passing is not allowed unless there are no placements available. There will always be a placement available to at least one of the players.

Objective

At the end of the game, the player with the most kings on the board wins. By that time, there will be no pawns remaining on the board. Optionally, a komi (compensation points) can be given to White in order to balance the game.