39h — Row Unique Nonempty

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.

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.

Gross return = 0.96 × captured stake × initial legal-board count ÷ current compatible-board count. It includes the stake; a positive return can be below the stake. Expected gross RTP is 96%, not a session guarantee. Certain mines and cells whose safe return would exceed 1,000 times the stake are disabled before a reveal. With no eligible cell, or after every safe cell is revealed, the current quote is banked automatically. Stake, mine count and refill lock during an active round; sound remains available. There is no auto queue. The initial wallet is 1,000 virtual coins. Only while idle with integer balance below 10, manual restoration sets integer balance to 1,000 and preserves carry. At settlement, add saved carry to gross return, credit the whole-number part and save the remainder. Balance and carry persist in this browser, including zero balance. Reloading an active round keeps its stake deducted without refund, return or resume.

A mine loses the captured stake and returns zero gross. A safe reveal changes the compatible-board count. Banking settles the current quote; it does not withdraw money or promise a profit.

A mine ends the round with zero gross return. After the first safe reveal, you may bank the current quote. Revealing every safe cell or reaching a state with no eligible reveal banks automatically. The cap is checked before a reveal: a cell is disabled if its safe quote would exceed 1,000 times the stake. A disabled cell is not a promise about a hidden board; it reflects the current compatible-board calculation.

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.

Gross return = 0.96 × captured stake × initial legal-board count ÷ current compatible-board count. It includes the stake; a positive return can be below the stake. Expected gross RTP is 96%, not a session guarantee. Certain mines and cells whose safe return would exceed 1,000 times the stake are disabled before a reveal. With no eligible cell, or after every safe cell is revealed, the current quote is banked automatically. Stake, mine count and refill lock during an active round; sound remains available. There is no auto queue. The initial wallet is 1,000 virtual coins. Only while idle with integer balance below 10, manual restoration sets integer balance to 1,000 and preserves carry. At settlement, add saved carry to gross return, credit the whole-number part and save the remainder. Balance and carry persist in this browser, including zero balance. Reloading an active round keeps its stake deducted without refund, return or resume.