X-O War

## Description

A 3-in-1 game: gomoku, renju, caro (vietnamese rule), with 3 difficult levels, and support multiplayer gameplay over Bluetooth.

Gomoku is a board game played with 2 kinds of stone, which players alternate in placing a stone of their color on an empty intersection. The winner is the first player to get an unbroken row of five stones horizontally, vertically, or diagonally.

Renju is an extended version of gomoku, but there are certain moves that Black is not allowed to make:
* Double three - Black cannot place a stone that builds two separate lines with three black stones in unbroken rows (i.e. rows not blocked by white stones).
* Double four - Black cannot place a stone that builds two separate lines with blocked four black stones in a row.
* Overline - six or more black stones in a row.

Black can win the game only by placing five black stones in a row (vertically, horizontally or diagonally).

White can win by either:
getting five (or more) white stones in a row
forcing Black to make a forbidden move (see above).

In Caro, popular among Vietnamese, the winner must have an unbroken row of five stones and this row must not be blocked at either end. This rule makes Gomoku more flexible and provides more power for White to defend.