Quartetto
Overview
Quartetto is a two-player abstract board game played on a common checkerboard that was invented in 2008 by Arty Sandler.

Board

The Quartetto is played on a common 8x8 checkerboard.

Each player has 4 checkers (dark and light). The initial location of the checkers is shown on the following picture:

Objective

The goal of the Quartetto is to place all own checkers in cells meeting the following conditions:

  1. Middle points of the cells should be vertices of some rotated square.
  2. The smallest bounding box containing the cells should be at least 5x5.

Below are several examples explaining the mentioned conditions:

Light checkers win by forming a square with appropriate bounding box (5x5). Dark checkers win by forming a square with appropriate bounding box (6x6).
Light checkers don't win: although they form a square but the bounding box is too small (3x3). Dark checkers don't win: the formed square isn't rotated.

Play

Players move alternatively one checker per turn, starting from the player with the dark checkers.

Checkers are moved horizontally or vertically any number of cells (exactly as rook in Chess).

Checkers cannot land on an occupied cell or jump over such cells.