How the Board Is Drawn
The board has four rows and four columns. Choose 3, 4 or 5 mines. Empty rows are allowed and may repeat. Only the nonzero four-bit row patterns must be distinct. The legal-board counts are 400, 1,264 and 2,928 respectively. Every board in the selected legal set has equal probability; the sampler uses cryptographic 32-bit draws with rejection to avoid modulo bias.
Gross Payout Calculation
The gross quote is determined by the following formula:
- Gross Quote = 0.96 × Captured Stake × (Initial Support Size / Current Compatible Support Size)
The factor 0.96 represents the gross return rate. The support ratio reflects the increasing difficulty as safe cells are revealed. The initial support size is the total number of legal boards for that mine count before any reveals.
Controls and Modes
Stake choices are 10, 20, 50, 100 and 200 virtual coins, with 20 selected initially. Mine choices are 3, 4 and 5, initially 3. Stake, mine count and refill lock during a round; sound remains available. Manual banking starts after the first safe reveal. A mine settles with zero gross return. Certain mines and cells whose safe quote would exceed 1,000 times the stake are disabled before a reveal. Revealing all safe cells, or having no eligible reveal remaining, banks the current quote automatically. There is no automatic queue, pause button, enforced timer or self-exclusion control.
Stopping Rules and Caps
A mine ends the round and returns zero gross. Manual banking is available after the first safe reveal. The game also banks automatically after all safe cells are revealed or no eligible reveal remains. Certain mines are disabled. The cap disables a transition before it is taken if its safe quote would exceed 1,000 times the stake; it does not truncate an already-earned return.
Rounded Payout Examples
Cell indices run from 0 to 15, row by row. These examples assume every listed cell was safe. Multipliers are rounded for display; the formula uses the compatible-board count.
| Mines | Safe path | Remaining boards | Gross multiplier |
|---|---|---|---|
| 3 | [0] | 325 | 1.1815 |
| 3 | [0,1,2] | 216 | 1.7778 |
| 4 | [0,1,2,3] | 405 | 2.9961 |
| 5 | [0,4,8,12,1] | 231 | 12.1683 |
Wallet and Persistence
The initial integer wallet is 1,000 virtual coins. When idle with an integer balance below 10, manual refill sets that integer balance to 1,000 while retaining fractional carry. Settlement adds the saved carry to the gross return, credits the whole-number portion and stores the remainder. Balance and carry persist in this browser, including a zero balance. Reloading an unfinished round keeps its stake deducted and ends it without refund, return or resume.
Frequently asked questions
Is this the official game from 39H?
No. This is an original demo by this independent guide. The name "Row Unique Nonempty" and its specific rules are described here. It does not certify or reproduce any outside product.
How is the payout calculated?
The gross payout is 0.96 times the captured stake, multiplied by the ratio of the initial legal-board support size to the current compatible support size after safe reveals.
What happens if the 1000x cap is reached?
Cells that would exceed the 1000x stake cap are disabled. If no eligible reveals remain, the current quote is automatically banked.
