Duel is the only mode where knowledge alone is not enough. Correct answers do not earn you squares, they earn you a currency — and what you do with it is up to you. It is Guess Ladder with a strategy layer on top, built for two people.
Seven squares lie between you: your house on the far left, your opponent's on the far right, five open squares in between. Square 3 is the middle. Both players start with one piece in their own house.
Get one of your pieces into the enemy house and you win immediately. That is six steps — and you have to be able to afford every one of them.
Every round begins with an estimation question that both players answer at the same time:
| Result | Diamonds |
|---|---|
| You are exactly right | 4 💎 |
| You are closer than your opponent | 2 💎 |
| Your opponent is closer | 0 💎 |
| Both exactly equally far off | nobody gets anything |
Diamonds do not expire. You can spend them immediately or save until you can afford something bigger.
| Action | Cost | Effect |
|---|---|---|
| Advance | 4 💎 | One of your pieces moves one square towards the enemy house. |
| New piece | 6 💎 | An extra piece appears in your house. You can have several pieces on the board at once. |
| Build tower | 8 💎 | A tower you can build only once per match. It stays for the rest of the game. |
| Pass | 0 💎 | Do nothing and save. |
You choose exactly one action per round. Both players decide simultaneously and in secret — you only see what your opponent did after the reveal.
Every round, after the actions, the tower fires automatically. It destroys one enemy piece that has advanced past the middle — always the one furthest forward, which is to say the most dangerous one.
That makes the tower a wall rather than a weapon. It does not stop your opponent reaching square 3, but every step beyond that costs them a piece. For 8 diamonds you buy peace in your own half — and the certainty that your opponent can only break through with several pieces at once.
If one of your pieces and an enemy piece land on the same square, they fight. Both players get the same question with two possible answers:
| You | Opponent | Result |
|---|---|---|
| right | wrong | Their piece is destroyed |
| wrong | right | Your piece is destroyed |
| right | right | Both pieces stay |
| wrong | wrong | Both pieces are destroyed |
That last case is the most expensive thing in the game: two pieces that cost at least ten diamonds between them, both gone after a single wrong answer.
With a single piece you are at your opponent's mercy: one lost fight or one tower shot sets you back completely. A second piece for 6 diamonds costs less than one and a half advances and makes you immune to exactly that.
Eight diamonds is two advances. Build the tower when your opponent is already on square 4 and they have covered half the distance anyway. Build it in the first few rounds and it shapes the entire match.
Spend four diamonds on an advance every round and you will never get past six. Passing once and then placing a new piece is often stronger than advancing continuously — especially when your opponent can see your lone piece walking helplessly into open ground.