Enclose: Dots and Boxes

The game from the back of an exercise book, played in chalk on a slate.

Dots in a grid. On your turn you draw one line between two neighbouring dots. Draw the fourth side of a square and you own it — and you draw again. Most squares when every line has been drawn.

That one extra clause is the entire game, and it is why dots and boxes is much harder than it looks. A turn is not a turn: close a box and you close the next one, and the next, until you run out. A chain of eight squares is eight moves by one player. So the middle of the game is not about taking squares at all — it is about running the board down to the point where your opponent has no safe line left and has to open a chain for you.

Then there is the move that looks like a mistake and wins the game. Near the end, when you have been handed a chain, taking all of it means drawing the last line, which hands the next chain straight back. Leaving two squares uncollected keeps the turn with your opponent instead. It is called a double-cross, it costs you two squares, and it usually costs them twenty.

The opponent gets stronger by thinking further ahead, not by being given anything. It understands chains, which is what most people's first hundred games do not.

Three board sizes, no timer, no move limit. Works offline, and there is nothing to buy.

Recent changes:
Fixes a bug that could take you out of a level after an ad. Smoother play.