Region Sum Lines Windoku by Philip Newman
(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
A storm at a certain Sudoku setter’s house precipitated a leak around one of the windows. Let’s hope your Windoku-solving skills are more solid than the weather-proofing was.

or solve online (using SudokuPad)
Theme: Leakin’ in the Rain
Author/Opus: This is the 125th puzzle from Philip Newman, part of the Genuinely Approachable Sudoku (GAS) team.
Rules: Standard Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). Each of the four 3×3 shaded regions must also contain the numbers 1 to 9 without repeats. Along each line, the numbers in every region it passes through have the same sum. (In this puzzle, for example, R4C5 + R5C4 = R6C3.)
GAS Time Standards (highlight to view): Two party hats (🎩🥳): 8:00; One party hat (🥳): 15:00. All other solvers earn a 🦕: Procrastinating Punatitan.
Thomas Hits the GAS (highlight to view): 3:11, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).
Solution: PDF; solving video with explanation to be added later from GAS team.
Note: Follow this link for other less common variations of Sudoku.
Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.
