Goal of the game
To claims the majority of the boxes.
A rectangular grid of dots, arranged in rows and columns, defines a grid of boxes, the dots being their corners. The grid starts empty.
At each turn, a player draws (fills) one of the box sides, connecting one dot to another one adjacent to it vertically or horizontally. The player may choose whatever side and the sides themselves belong to nobody.
Only when a box is completed (its fourth side is drawn), the player completing the box claims it and fills it with his own colour. Once the box claimed, the player has to fill another empty box side (and so on, as long as each action completes another box).
When all the box sides are drawn, the player who claimed the most boxes wins.
With some sizes, a variant may played which uses a kind of pie rule to compensate for the advantage of the first player. The first player plays up to a certain number n of turns drawing sides; the first player may decide to stop anytime after drawing the first side and the colours are (implicitly) assumed to alternate as during regular gameplay.
At this point, the second player chooses between keeping the same colours or swapping them between the two players and the player with the next playing colour plays next.
From this point on, players alternate as during regular gameplay.
At the time of writing this page, only the 5 boxes × 5 boxes size may use the pie rule and the first player may draw up to 5 sides during the setup phase.