What it is

Dots and boxes, the game everyone has played on the back of a page. Join two dots; close the fourth side of a square and it is yours, and you go again. Most boxes at the end wins.

It is the second game here two people can play at once, and the first that is turn-based. Far End proved that a shared screen works; this proves the idea generalises beyond one game.

There is no mode to choose

The grid plays itself until a hand touches it. The first tap on a line takes whichever colour is to move, and that person owns it for the rest of the match. One player, two players, and somebody joining on move twenty are the same code path rather than three.

A fresh board sits still for fifteen seconds before the computer starts playing itself, shown as a bar that empties — the only moving thing on screen while it lasts. That is a door held open: two people arriving together both get a chance to take a side rather than one of them finding a game already under way. A board that already has somebody on it skips the wait entirely, because that is a rematch and not an arrival.

Far End's two seats are a place — a hand can only be at one end of the table. Here the seat is simply whoever is to move, so an impatient tap during the computer's turn would quietly take the second colour and the board would stop with nothing on screen explaining why. A short grace period after your own move lands stops that, while a deliberate touch on a labelled seat is always allowed through.

The opponent is three opponents

Not a slider and no probability knobs. Each of the three knows exactly one more endgame rule than the one below it: take every box you can; never hand one over while a harmless move exists; and, at the top, give up the last two boxes of a chain on purpose so you are the one who opens the next.

It steps up a tier when you beat it and down when it beats you, so nobody sets anything. After two minutes with nobody there it returns to the gentlest tier, which means a stranger always meets the easy one.

None of the three counts long chains during the opening. That is the thing that would make it effectively unbeatable, and it is withheld on purpose. The ceiling is a decision rather than a gap.

How to play

Take a colourTouch any line
Draw a lineTap the gap between two dots
Close a boxDraw its fourth side — then go again

Two people simply touch the board on their own turns. Nobody agrees on anything first, and a second person can join in the middle of a game.

On a desktop, click instead of tapping and nothing is behind a key. Unlike Far End, the two-player game works fine with one mouse here, because the turns are separate in time rather than in space.

Walking away

Somebody stands up mid-game and never comes back, which is the problem a screen in a public room actually has. A seat that has not been touched for thirty seconds goes back to the computer and the board carries on playing rather than freezing. Ten seconds after a result, a fresh board appears with both seats free, so the next person finds a clean start rather than a stranger's position.

What isn't settled yet

Whether two people who have never seen it will both put a hand on the board without either asking a question. Nothing that runs in a browser can test that.

The grid is five by five. Bigger makes a game run long for a room where people are waiting; smaller and it is solved after two plays. That number is a judgement, not a measurement.

Build Log

Credits and licences

No third-party engine and no embedded typefaces — it uses whichever fonts your device already has. Cover art was created with Manus.

Fourth Side is original work by Launchway Games.