---
title: "X-Wing: Two rows, the same two columns"
description: "An X-Wing has a digit in exactly two possible cells in each of two rows, in the same two columns. Learn which candidates this pattern rules out."
lang: "en"
canonical: "https://unisu-sudoku.app/en/sudoku-techniques/x-wing/"
---

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Further techniques

# X-Wing: Two rows, the same two columns

An X-Wing occurs when a digit has exactly two possible cells in each of two rows, in the same two columns. The digit can be removed from other cells in those columns.

![Unisu lesson on X-Wing, showing the explained grid](https://unisu-sudoku.app/_astro/en.BXzF_Yjz_1vdfVg.webp)

An X-Wing occurs when a digit has exactly two possible cells in each of two rows, in the same two columns. The digit can be removed from other cells in those columns.

## An example from the app

In row 6, row 8, candidate 2 is confined to column A, column E. There are 2 starting lines and exactly 2 crossing lines.

The 2 required placements of 2 occupy column A, column E. In those lines, 2 is ruled out outside row 6, row 8.

These notes are therefore ruled out: A5: 2; A9: 2; E4: 2; E9: 2.

The image shows the candidates relevant to this step. A note being hidden does not mean it has been logically eliminated.

## Practice the next step

A rectangle alone is not enough. The two starting rows must have no other candidates for that digit.

In the app, follow the reasoning in the matching lesson and try a task yourself. With a new puzzle, always start from its actual candidate state.

## Questions about X-Wing

### Are four candidates forming a rectangle enough?

No. Each starting row must allow the digit only in the same two columns.

### Where can I eliminate in a row-based X-Wing?

In the two cover columns outside the starting rows. The four starting positions remain reserved for the digit.

### Can I start an X-Wing from columns instead?

Yes. Two columns become the starting areas and two rows the cover areas; the elimination direction changes accordingly.

### Do the cells’ other candidates matter?

This pattern follows one digit. Other candidates do not invalidate it if the restrictions for that digit hold.

### How does Swordfish differ?

Swordfish uses three starting areas and three cover areas. X-Wing uses two of each.

## Keep practicing in Unisu

Download Unisu for iPhone or Android. Solve a puzzle or work through a guided lesson on the technique.

-   [Download on the App Store](https://apps.apple.com/us/app/id6775824061?l=en)
-   [Get it on Google Play](https://play.google.com/store/apps/details?id=app.unisu.sudoku&hl=en)

## Useful before this guide

### Sudoku pencil marks: track and update candidates

[Read more: Sudoku pencil marks: track and update candidates](https://unisu-sudoku.app/en/sudoku-techniques/pencil-marks/)

### Locked Candidates

[Read more: Locked Candidates](https://unisu-sudoku.app/en/sudoku-techniques/locked-candidates/)

## Where to go next

Further techniques

Unisu · Oct 27, 2026

### [Swordfish: Follow one digit across three lines](https://unisu-sudoku.app/en/sudoku-techniques/swordfish/)

A Swordfish confines a digit’s candidates in three starting rows to exactly three columns. The three required placements use those columns.

Unisu

### [Learn Sudoku: a path from rules to techniques – Unisu](https://unisu-sudoku.app/en/learn/)

Start with the rules, get comfortable with pencil marks and choose a technique for the situation you’re working on.

Download app

## Ready for a puzzle? Take a moment.

Download Unisu on your phone. Start a Sudoku or choose a lesson on the technique you want to understand.

-   [Download on the App Store](https://apps.apple.com/us/app/id6775824061?l=en)
-   [Get it on Google Play](https://play.google.com/store/apps/details?id=app.unisu.sudoku&hl=en)

![The daily challenge in Unisu](https://unisu-sudoku.app/_astro/en.C-sYR9hJ_1QwI9G.webp)

![A classic Sudoku game in Unisu](https://unisu-sudoku.app/_astro/en.C6DJ1kiE_2dRWDN.webp)