DotDuel strategy guide
DotDuel has no luck: both players see the whole board, so every point is won or given away by a decision. These are the ideas that separate a Beginner bot from an Impossible one.
1. Never leave a line one dot short
The most common beginner mistake is placing a dot that leaves a line with a single empty spot. Your opponent simply fills it and scores the whole line. Before every move, look at every line through the spot you're about to take, not just the one you're thinking about. On Triangle that's three lines per dot; on Square and Rectangle it's four.
2. Count what your move gives away
A good habit: for each candidate move, ask two questions. What do I score now? and What is the best my opponent can score in reply? A move worth 3 that sets up a 7 for your opponent loses you 4 points. The Hard bot plays exactly this way, and it's why it feels so much tougher than Medium.
3. A double completion can be a gift
When one dot finishes two lines, you score only the longer one and the shorter one goes into the shared pool of waiting lines, where your opponent can take it on their very next turn. Finishing a 6 and a 4 together nets you 6 but probably gives your opponent 4. Finishing them on separate turns, when you can, may get you both.
4. Waiting lines are spare moves
Claiming a waiting line uses your turn without placing a dot. That makes it a perfect waiting move. In the middle game you'll often reach a position where every empty spot would set up a line for your opponent. If there's a waiting line on the board, claim it instead: you score, the board doesn't change, and now your opponent has to make the risky move.
That's also why grabbing every waiting line immediately isn't always best. A small line left in the pool can be worth more later, as the move that lets you avoid opening a big one.
5. Watch the long lines
Lines are worth their length, so the long ones decide games. On Triangle the top row is worth 8 and the long diagonals 7 or 8, while corners are worth 1. Keep track of how many empty spots are left on the longest lines, and try to be the player who takes the last one, not the second-to-last.
6. Plan the endgame
Once every dot is coloured, the game becomes claims only: players alternate taking waiting lines until none are left, and each player will naturally take the longest one available. Before you place the last few dots, count the waiting lines and their lengths. Whether the pool has an odd or even number of lines decides who gets the big ones, and a single tempo move earlier can flip it.
7. Each shape plays differently
- Triangle: three line directions and short lines near the bottom. Positions stay readable, which makes it the best shape for learning to count. Moving first or second matters here, which is why ranked games against bots flip a coin for the first move.
- Square: four directions, including both diagonals. Single moves complete several lines much more often, so the waiting-line pool grows quickly and tip 4 becomes your main weapon.
- Rectangle: the biggest board, with the longest games and the most waiting lines in the endgame. Patience and counting pay off most here.
8. Practise against the bots
| Bot | How it plays | What it teaches |
|---|---|---|
| Beginner | Random moves | The rules and how lines complete |
| Easy | Takes corners and big obvious lines | Spotting free points |
| Medium | Always takes the most points right now | Not leaving lines one dot short (tip 1) |
| Hard | Weighs its gain against your best reply | Counting what a move gives away (tip 2) |
| Impossible | Looks two moves ahead and values the waiting lines | Tempo, waiting lines and endgame parity (tips 4–6) |
Not sure about a rule? Go back to How to play.