Advanced

X-Wing Master Logic

Use rectangle intersections across parallel rows or columns to eliminate candidates.

Interactive Practice

Find the number for the highlighted cell

Apply Technique

Find the number for the highlighted cell:

X-Wing Master Logic

An X-Wing occurs when a candidate appears exactly twice in two parallel rows, and those candidates align in the exact same two columns (forming a rectangle).

Rules:

Find two parallel rows where digit N can only go in column A and column B.
Because N must be in column A in one row and column B in the other, no other cells in column A or column B can be N.
Eliminate candidate N from all other cells in column A and column B.

Hint

Can be applied row-based or column-based.
Look for candidates that appear only twice per line.