Daily Challenges

The 1-1-X Pattern: Guaranteed Safe Cells

The 1-1-X is the logical opposite of the 1-2-X rule. Where 1-2-X finds mines, 1-1-X finds safe cells. When two “1"s start from a wall edge, the third unrevealed cell (X) is always safe to click.

This pattern is incredibly valuable because safe clicks expand your revealed area, giving you new information to work with.

Also known as: 1-1 pattern, 1-1+ (extended form). The “+” variant applies when additional revealed cells are present beyond X.

How It Works

Three unrevealed cells (A, B, X) sit above a wall. Below them: a wall end, a “1”, and another “1”.

  • The first “1” touches cells A and B → one mine in {A, B}.
  • The second “1” touches cells A, B, and X → one mine in {A, B, X}.

The first “1” already accounts for the single mine in {A, B}. The second “1” also needs exactly one mine, and since that mine is already in {A, B}, X must be clear.

$$\text{mines in } {A, B, X} - \text{mines in } {A, B} = 1 - 1 = 0 \text{ mines in } {X}$$

X is safe. Click it.

Why 1-1-X Complements 1-2-X

The 1-2-X and 1-1-X rules are two sides of the same coin — constraint subtraction:

Pattern Subtraction Result for X
1-2-X $2 - 1 = 1$ Mine
1-1-X $1 - 1 = 0$ Safe

The only difference is the second number. A “2” leaves one mine unaccounted for (mine at X). A “1” leaves zero mines unaccounted for (X is safe). Learning both patterns together makes them easier to remember.

Where to Find 1-1-X

Along Walls

The classic location. Two “1"s in a row starting from a wall edge. Look for the third unrevealed cell past the “1"s — that cell is safe.

On Interior Boundaries

1-1-X works along any boundary where numbers have unrevealed cells on only one side. The two “1"s must be at the end of the known region.

After Reduction

A sequence of 2-2 with a flag touching each number reduces to 1-1. Apply 1-1-X to the third cell.

What Happens After Clicking X

When you click the safe cell X, it reveals a number (or blank). This new information often creates additional solvable patterns:

  • If X reveals a “0” (blank): Auto-expansion opens a large region, giving many new boundary numbers to work with.
  • If X reveals a number: That number creates new constraints on its neighbors, potentially enabling further deductions.
  • If X helps satisfy an adjacent number: The revealed cell may enable a chord on nearby numbers.

This cascading effect is why 1-1-X is strategically powerful — it progresses the board.

Common Variations

1-1-X Around Corners

The pattern works around wall corners too. See 1-1 Corner Pattern for the complete guide on this variation.

2-2-X (Reduced)

If both “1"s are actually “2"s that each touch one flag, they reduce to “1"s. The X cell is still safe.

Reversed Direction

Like all wall patterns, 1-1-X works in any orientation — horizontal, vertical, reading left-to-right or right-to-left.

Distinguishing 1-1-X from 1-2-X

The critical difference is the second number:

  • 1-1-X: Second number is “1” → X is safe
  • 1-2-X: Second number is “2” → X is a mine

Mixing these up is a game-ending mistake. Always double-check the second number before acting. With practice, the distinction becomes automatic.

Practice Tips

  1. Pair with 1-2-X scanning. When scanning walls, check both patterns simultaneously. If you see “1-1,” the next cell is safe. If you see “1-2,” the next cell is a mine.
  2. Click X first. Revealing a safe cell gives new information. If you see both 1-1-X (safe click) and a known mine elsewhere, click the safe cell first — the revealed number may make the mine deduction clearer.
  3. Look after every flag. When you flag a mine using 1-2-X, the flag may reduce adjacent numbers, creating a new 1-1-X pattern.