Dots and Boxes
Rules
Dots and Boxes is played on a grid of dots. On your turn, draw one line connecting two dots that are next to each other, either across or down. Whenever a line you draw closes the 4th and final side of a box, you claim that box and go again — and if one line happens to close two boxes at once, you claim both and still go again.
When every line on the board has been drawn, whoever has claimed the most boxes wins.
New to this one? Medium is a good place to start — it plays the same sound fundamentals as Hard right up until a chain has to be opened, then picks blindly instead of minimizing the damage. That's usually where the game turns.
Controls
Dots are labeled by column letter and row number — letters across the top, numbers down the side. A line connects two neighboring dots, so "a1-b1" means the line between dot a1 and dot b1.
With a mouse or touchscreen: click any faint dashed guide line between two dots to draw it there.
With a keyboard: type the two dots into the box below the board — "a1-b1", "a1,b1", "a1 b1", and "a1b1" are all read the same way — then press Enter or Draw.
Type status (or just the start of it, like "sta") and press Enter or Draw at any time to have the whole board read back to you.
Roots
Dots and Boxes dates back to at least the 1800s, first written up by French mathematician Édouard Lucas as "la pipopipette." Its whole strategic depth comes from one tension: drawing a line that leaves any box at 3 sides hands your opponent a free box next turn, so strong players spend most of the game avoiding that until they're forced into it — then try to give away as little as possible. For a related pinning-and-territory game in this collection, see Crack'd Mirror.
Under the hood
Easy is a coin flip more than a strategy: given a free box to take, it grabs it 60% of the time and otherwise just moves at random, so it hands away chains constantly without meaning to. Medium and Hard both play the obvious first half of real Dots and Boxes strategy correctly — always take every free box available, and while there's nothing free on the table, only ever play moves that don't leave a box at three sides for the opponent to grab. Once every remaining move does leave some box exposed — the moment a chain has to be opened — their paths split. Medium picks blindly among the bad options. Hard looks one move ahead: for each opening it could make, it simulates the opponent grabbing everything they can get for free afterward — using the exact same greedy-capture logic the AI itself uses to take boxes, just pointed at the other side — and picks whichever opening gives away the least.
That's a genuinely useful heuristic, but it isn't the real expert technique. Competitive Dots and Boxes play revolves around the double-cross: when you're forced to open a chain, you open the shortest one, and even then you leave the last two boxes of it untaken rather than sweeping the whole thing — sacrificing two boxes on purpose to hand the move back to your opponent, forcing them to open the next chain instead of you. None of the AI here plays that way. Hard's one-move-ahead check only asks "how much does this give away right now," not "who ends up controlling the rest of the game" — so a player who's actually learned real double-cross theory has genuine room to out-play even Hard.
That's also, honestly, why this is the one game on the site where the AI isn't really the reason for the high skill ceiling. Where Battle Grid's ceiling is capped no matter how good the algorithm gets, because the missing information is about the other player's hidden fleet, Dots and Boxes' ceiling stays open specifically because the real strategy is deeper than what's built in here — the game itself has more room in it than any of its three difficulty levels currently uses.