Copyright (c) ? Mauro Vanetti

Doh! is played on an empty 6x7 square board.

SQUARE - A set of four stones of the same color making a square. They can be, horizontal, diagonal and oblique (see samples).
A square is advised if the player says on the previous turn, that he is going to make it.
By convention, the 4 board edges are also considered a square.
DROP - Each player chooses a column, and then drops a stone on the lowest possible empty cell (the lowest row is the bottom row).
GOAL - Wins the player that makes an advised square.
Some squares

The unmarked black stones show a horizontal square.
The unmarked white stones show the special board square.
The marked white stones show a diagonal square.
The marked black stones show an oblique square.

This game, a variant of Connect 4, also reminds the square formations of Hip. The rules were translated from this webpage.