Minefield is Minesweeper on the three classic boards, with the two things that separate a casual clone from a real one: a first click that is always safe, and chording. This page covers both, plus what the efficiency figure on the results screen is actually telling you.
Objective
A number counts the mines touching that square, counting all eight neighbours. Flag the mines, uncover everything else. Your first click is always safe.
Boards
| Level | Grid | Mines | Density | Hints |
|---|---|---|---|---|
| Easy | 9 × 9 | 10 | 12.3% | 3 |
| Medium | 16 × 16 | 40 | 15.6% | 2 |
| Hard | 30 × 16 | 99 | 20.6% | 1 |
These are the standard beginner, intermediate and expert dimensions, and the density column is the part that matters. At Easy's 12% almost every position can be reasoned out, so a loss is nearly always a misread. Hard's 21% is dense enough that the expert board regularly produces a genuine 50/50 with no logical answer — that is a property of the classic layout, not a flaw, and it is why the hint budget shrinks as the boards grow.
Controls
| Action | Mouse | Touch | Keyboard |
|---|---|---|---|
| Dig | Left click | Tap | Space |
| Flag | Right click | Long press | F |
| Chord | Left or middle click a number | Tap it | Enter |
| Move cursor | — | — | ← ↑ → ↓ |
| Hint | — | — | H |
| Restart | — | — | R |
The Flag button in the top bar swaps tap and hold, which beats long-pressing every mine on a phone. It swaps left and right click too.
Chording
Chording means clicking a number that already has all its flags placed, to clear everything else around it in one action. One flag plus one chord routinely replaces three to five separate clicks, and it is how the game is played at any speed at all.
It trusts your flags. A chord on a number with a wrong flag beside it will happily uncover a mine, so it is as fast as your flagging is accurate.
Reading your result
The results screen reports 3BV: the fewest left-clicks a perfect player would need on that exact board. Each connected region of zeros counts as one click, because it floods open; every other safe square that no such region touches has to be clicked on its own. Two figures come out of that:
- 3BV/sec — your speed, and the standard way times are compared across boards of different luck.
- Efficiency — 3BV divided by your clicks. 100% means you never wasted one. Chording is how you get near it, and above 100% is real and earned, because a single chord can resolve several 3BV units at once.
Both are shown only on a win. On a lost game they divide a whole-board figure by a handful of clicks and read absurdly kindly — an abandoned board once scored 157%.
How the first click stays safe
Mines are laid after your first click, and never on the clicked square or any of its eight neighbours. That guarantees the opening square has zero adjacent mines, so it always floods open a region. There is no opening coin flip.
The flood fill also stops at flags, which is what lets you protect a square you have already reasoned about from being swallowed by a cascade.
Hints prefer logic over luck. Two standard deductions run first — a number whose flags are all placed frees its remaining neighbours, and if one number's hidden set is a subset of another's needing the same count, the extra squares are safe. Because those rules trust your flags, a mis-flag could make them point at a mine, so every result is screened against the real board before it is shown. A hint must never be the thing that kills you.
Strategy
- Learn the 1-2-1 and 1-2-2-1 edge patterns. They solve themselves on sight and cover a large share of any board.
- Chord constantly. The efficiency figure rewards it directly, and it is the only route to a competitive time.
- Flag first, then chord the neighbourhood, rather than digging square by square.
- On Hard, accept that a genuine 50/50 will happen. That is the board, not you.
Questions
Can I lose on the first click?
No. Mines are placed after it, avoiding that square and all eight neighbours.
What is a good efficiency?
100% means no wasted clicks. Strong chord play goes above it — one chord can resolve several 3BV units, so 130% and up is achievable on Expert.
How do I chord on a phone?
Tap a number that already has all its flags. Use the Flag button to swap tap and hold.
Are there no-guess boards?
No. Boards are classic random layouts, so Hard will occasionally hand you a true 50/50 — the same as the original.
Other guides
- Gold Miner — the price board, TNT chains and the winch
- Fruit Cascade — cascade multipliers and special fruit
- Merge Numbers — the merge-once rule and corner strategy
- All guides