Deep Six is a free online Minesweeper reimagined as a sonar sweep through sunken wreckage — read the numbers, flag the naval mines, and clear every safe tile before the depth gauge catches up. Classic presets, a Custom board, relaxed Zen, and a seeded Daily Challenge, with a real no-guess solver behind the Hint button. No download required.
🕹️How do you play Deep Six online?
- 1Reveal a tile by tapping it — a blank tile means no mines touch it, so its neighbors open automatically in a cascading ripple.
- 2A numbered tile tells you exactly how many mines are hiding in its up-to-8 neighboring tiles — never more, never less.
- 3Right-click (or long-press on mobile) a hidden tile to flag it as a suspected mine, protecting it from an accidental reveal.
- 4Once a numbered tile's flag count matches its number, tap it again to chord — instantly revealing every remaining unflagged neighbor.
- 5Your very first click of a run is always guaranteed safe; mines are placed only after it, and never underneath it.
📋What are the rules of Deep Six?
- ▸Every non-mine tile shows the count of mines among its neighbors; a 0 opens automatically with all its connected neighbors.
- ▸Chording only fires when a revealed number's surrounding flag count exactly matches that number — a wrong flag can still cost you.
- ▸The mine counter shows mines remaining minus flags placed, and can go negative if you over-flag.
- ▸You win the moment every non-mine tile is revealed — flags on the mines themselves are optional, just a celebration flourish.
- ▸Hitting a mine reveals the full board immediately, marking the triggering mine and any incorrect flags distinctly.
💡What are the best tips for winning at Deep Six?
- ★Chord aggressively once flags are placed correctly — it is the single biggest speed gain over clicking cells one at a time.
- ★When you are stuck, scan for a number whose unflagged-neighbor count equals its own number first — that is always a guaranteed set of mines.
- ★Save your limited hints for genuine dead ends — the honest "this needs a guess" message is itself useful information.
- ★On Hard and Expert+ boards, clear the edges and corners first; they have fewer neighbors and resolve with far less ambiguity.
- ★In Zen mode, use your one forgiven mistake deliberately to test a 50/50 guess rather than wasting it on a careless click.
ℹ️What is Deep Six?
Deep Six takes the century-old logic of Minesweeper and drops it to the ocean floor: a sonar-buoy drone named Bleep sweeps a grid of hull plates for old naval mines, and every tile you clear is one step closer to the surface. The number colors follow the convention Minesweeper players already know by heart, so the logic transfers instantly even though the theme is new. Under the hood, a real deduction engine runs the same satisfied-number and subset logic a sharp human player would use — it powers an honest Hint button that will tell you plainly when a spot needs a real guess, plus an optional Fair Board mode that regenerates a board until it is provably solvable without guessing. Four modes cover every mood: Classic runs the four standard competitive presets with a saved best time each, Custom lets you build any grid within sane limits, Zen forgives one wrong click so newer players can learn chording and flagging without a hard stop, and the Daily Challenge deals a seeded board shared by the date, building a streak the longer you keep it up.