Slither
Overview

Slither is a two-player abstract board game invented by Corey Clark in 2010. This game is a member of the connection game family, including such game as Hex, Crossway or Chain Lightning .

Board

Slither is played on a square grid of 15x15 intersections (points). Smaller boards (13x13 or 10x10) can also be used by beginners or for quick games. The left and right edges are colored white while the top and bottom edges are colored black:

Object of the Game

The goal of Slither is to form a chain of your stones connected orthogonally (horizontally, or vertically) linking the opposite edges of the board marked by your color. A corner is considered to be part of both adjoining edges.

No draws are possible in Slither

Play

The game begins with an empty board.

Each player has an allocated color: White and Black. Black plays first, then turns alternate.

A player's turn proceeds as follows:

  • First, the player may (but is not required to) move one of their stones already on the board to an orthogonally or diagonally adjacent empty point.
  • Next, the player must place a new stone of their color on any empty intersection of the board, after which the turn ends.

After the turn is completed, all of a player's stones that are diagonally adjacent must also be connected orthogonally through a common like-colored neighboring stone. Otherwise, the move is illegal.

If a player has no moves available on their turn, they must pass. Passing is otherwise not allowed.

The pie rule is used to make the game fair. This rule allows the second player to switch places with the first player after the first player makes their first move, if they think that the first player has made an especially good move.

Advanced rules
 In Advanced Slither, a stone can only be moved if it's orthogonally adjacent to at least one stone of any color.