About Gomorpion
Gomorpion is a variation of Gomoku. The aim of Gomorpion is fundamentally the same
as Gomoku's in that each player is trying to connect five of his pieces in a row. In Gomorpion after a player connect five pieces this constitutes a cast(set). At the end of each cast
both player's pieces are marked off(see here)
and the game continues until a player cannot make a legal move or resigns. The pieces captured after each cast is over count as one point each towards the winner of that cast.
The winner is the player with the most points at the end of the game.
Formal Rules
In Gomorpion each player takes turn making moves on the intersections of lines on a 30x30 board.
When a player succeeds in connect five or more of his pieces in a row(horizontally, vertically, diagonally) this marks the end of a cast and a straight line is drawn from each of the pieces captured in that cast to
other neighboring pieces captured in the same cast (see here). If a captured piece does not have any other piece neighboring it that were captured in the same cast a circle is drawn around it. The pieces captured after each cast is over count as one point each towards the winner of that cast.
At the end of a cast(set):
1) A piece is captured if it is neighbored by 4 or more pieces belonging to the winner of the cast. The neighboring pieces can be from the current cast or any other casts as long as they belong to the winner of the current cast
(see here) .
2) A piece shifts to the next cast if it is of the same color as the winner and is bordered by less than 4 pieces belonging to the winner (see here)
3) A piece is recapturable(can be recaptured) by the loser of the cast if it is of the same color as the loser and surrounded by less than 4 of the winner's pieces. A recapturable piece is designated by drawing a circle(blue/red) around it.
4) A piece is recaptured(rescued) if it is part of a chain of 5 or more pieces of the same color; basically, if it is part of the chain of pieces that won the cast (see here).
5) An intersections is said to be sieged by a player if at the end of a cast the intersection is unoccupied and surrounded by pieces belonging to the player or an edge of the board. A player can have as many sieged intersections as possible.
Two adjacent intersections can be sieged by a player if they are both surrounded on all sides by pieces belonging to the player, except by the other empty adjacent intersection (see here).
6) Red cannot play in an intersection sieged by Black and vice versa.
7) A siege can be broken by an opponent if the surrounding pieces contains pieces that have shifted or are recapturable (see here).
8) A piece is safe if it is played on a sieged intersection provided the siege is not broken by the opponent. When the cast is finished the point goes to the owner of the siege regardless of who won again provided the siege is not broken. A circle is drawn around a safe piece(white for black/yellow for white) (see here).
Game Over
A game is over if a player cannot make a legal move, i.e., there are no free intersections or the free ones are sieged by the opponent. Since Red goes last if Red cannot play and Black cannot play, then the cast is a draw no player gets the points. If Red cannot and Black can, then Black wins and gets the points for that the last cast. If Red can play and Black can't Red wins the last cast and gets the points. The winner of the game is the player with the most overall points.