Number Duel → Games → Product Duel
Product Duel Rules and How to Play
Product Duel is the official multiplication mode in Number Duel. Each player controls one active factor. Multiply the two active numbers to create the center target, then claim an open board cell with that value. The first player to connect four claimed cells wins.
This page covers the rules and turn flow. For classroom use and multiplication-fluency guidance, see the free multiplication game guide. For advanced tactics, use the Product Duel strategy guide.
Open Number Duel and choose Product Duel →
Product Duel at a Glance
| Board | 5×5 grid of product values |
|---|---|
| Selectable factors | 1 through 9 |
| Target | Your active factor × your opponent's active factor |
| Legal move | An open cell equal to the current product target |
| Win condition | Connect four claimed cells horizontally, vertically, or diagonally |
| Stalled play | Change factors when possible; pass only when no factor creates a legal claim |
How to Start Product Duel
- Open Number Duel.
- Choose bot play, then select Product Duel from the rule modes.
- Check both active factors and the product shown in the center target.
- Choose your factor, then claim one of the highlighted cells matching the product.
- Continue until one player connects four cells or the board reaches a draw.
Selecting a factor and claiming a cell are parts of the same turn. Changing your active factor changes the product target, so the highlighted legal cells update before you claim.
Example Turn
Your opponent's active factor is 5. You choose 4, so the product target becomes 20. Every open cell labeled 20 is legal and lights up. You claim one highlighted cell, ownership changes to your color, and the turn passes to the opponent.
On the next turn, the opponent may choose 7 to create target 35. If no open 35 cell remains, that choice cannot produce a claim; the opponent must select another factor that creates a legal target when one is available.
Changing Factors, Passing, and Draws
You cannot pass while a legal claim exists. If the current product has no open matching cell, try another factor from 1 through 9. Passing is allowed only when none of those factor choices creates a legal claim against the opponent's active factor. When no remaining board value can be reached, or play cannot continue after passes, the game records a draw.
How Product Duel Is Won
A winning line contains four cells owned by the same player. The line may run horizontally, vertically, or diagonally anywhere on the 5×5 board. The game ends as soon as a valid line is completed; unused cells do not need to be filled.
Product Duel vs. Sum Duel
| Rule | Product Duel | Sum Duel |
|---|---|---|
| Number operation | Multiply the active factors | Add the active numbers |
| Selectable numbers | 1–9 | 0–12 |
| Board target pattern | Product values such as 12, 20, 24, and 35 | Sum values across a more compact range |
| Winning line | Connect four | Connect four |
Choose Sum Duel when you want the addition version of the same board-control rules. Choose Product Duel when the target should be created by multiplication.
Other Number Duel Modes
Product Duel uses multiplication. Sum Duel uses addition for a more flexible board. Subtraction Duel uses subtraction. Division Duel uses division. Fifteen Duel drops the number rack entirely and uses a 3x3 make-15 puzzle. All modes are free to play in any modern browser.