Zipper Lines Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
In a Zipper Lines Sudoku, each line has a key value at its center that defines how all the remaining pairs of cells get filled in. Can you work through this pattern of lines to the one solution?

Zipper Lines Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Learning to Fly

Author/Opus: This is the 34th 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). For each line, the numbers in each pair of cells an equal distance away from the center of the line must sum up to the value in the central cell of the line. (In this puzzle, the lines that cross go straight through those cells; this means, for example, R6C2 + R6C4 = R6C3 from the Zipper Lines rule.)

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:00; One party hat (🥳): 14:00. All other solvers earn a 🦕: Examined Elosaurus.

Thomas Hits the GAS (highlight to view): 3:24, 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.

Ratio Pairs Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
There are only black circles in this simplified version of a Kropki Pairs Sudoku, so you’ll be focusing on doubling or halving certain values to make some of the key placements.

Ratio Pairs Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Don’t Come Around Here No More

Author/Opus: This is the 33rd 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). If a black circle is given between two adjacent cells, then the two numbers must have a ratio of 2. Pairs of cells without circles can have any relationship.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 6:30; One party hat (🥳): 13:00. All other solvers earn a 🦕: Cyclical Caieiria.

Thomas Hits the GAS (highlight to view): 2:08, 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 and solving video with explanation 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.

XV Pairs Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
With the end of the August guessing game, we’re starting to see new themes again from GAS starting with this highly symmetric XV Pairs Sudoku puzzle from Philip.

Factor Lines Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Breakdown

Author/Opus: This is the 32nd 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). Whenever an X or V, reflecting the Roman numerals for 10 or 5, is placed on the edge between cells, the numbers in the two adjacent cells must sum to exactly 10 or 5. (Pairs of cells without an X or V mark can have any sum value.)

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 6:00; One party hat (🥳): 12:00. All other solvers earn a 🦕: Baalsaurus, Breaker of Hearts.

Thomas Hits the GAS (highlight to view): 2:04, 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 and solving video with explanation 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.

Factor Lines Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
Each line in this intriguing puzzle is connecting pairs of factors, so thinking of what numbers can come together and which cannot is essential throughout most of the solve.

Factor Lines Sudoku by Philip Newman

PDF

or solve online (using SudokuPad);
[update 2025-08-29-10:00 AM PT] see also the author’s “fixed” version in SudokuPad which adds a given but is similar in difficulty. This version did not survive typesetting so we never saw it until after our own publication here. There have been a lot of asymmetric puzzles this month and we don’t directly edit the GAS except to confirm valid puzzles and reasonable times; we’ll discuss together if / how we do patches in the future if GAS make changes after our publishing.

Theme: The Cold, Hard Factors

Author/Opus: This is the 31st 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). For every pair of adjacent values connected by a line, one number is a multiple or a factor of the other. It is possible for a number to be adjacent to itself on a line. (For example if R3C4 were 3, then R2C3 which is connected to R3C4 could be 1, 3, 6, or 9, because 1 is a factor of 3, 3 is a factor and multiple of itself, and 6 and 9 are multiples of 3.)
The color of the lines in this puzzle is for artistic purposes only.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 8:00; One party hat (🥳): 24:00. All other solvers earn a 🦕: August Austroposeidon.

Thomas Hits the GAS (highlight to view): 3:27, 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 and solving video with explanation 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.

Quad Max Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
The largest numbers around some sets of cells are marked, but can those pointers show you where all the logic sits to solve this interesting puzzle that doesn’t give any very large values?

Quad Max Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Quadrennial Maxis Sudoku

Author/Opus: This is the 30th 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). An arrow in the grid points to the largest value in the four surrounding cells. Numbers may repeat around an arrow clue, but the largest value must be unique.
(In this puzzle, for example, R2C1 is bigger than R1C1, R1C2, and R2C2.)

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:30; One party hat (🥳): 15:00. All other solvers earn a 🦕: August Adamantisaurus.

Thomas Hits the GAS (highlight to view): 3:16, 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 and solving video with explanation 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.

Step by Step Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
Sudoku often has you following a long chain of logic around the grid; this variant should give you some of that flow in an “approachable” way.

Step by Step Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: From the Sublime to the Ridiculous

Author/Opus: This is the 29th 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. Also, all arrows must be connected in a single cycle traveling around the grid; the number placed in each arrow indicates the number of cells away the next arrow visited in the cycle is.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:00; One party hat (🥳): 13:00. All other solvers earn a 🦕: August Atlasaurus.

Thomas Hits the GAS (highlight to view): 1:47, 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 and solving video with explanation 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.

Bust Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
This puzzle combines regular Sudoku logic with ideas from the card game Blackjack. Tell us in the comments if you think it is a hit or not?

Bust Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Bust a Move

Author/Opus: This is the 28th 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. Also, the clues outside the grid are inspired by Blackjack and show when a player has gone “Bust”. Specifically, for a clue N, the sum of the first N numbers in that direction in that row or column is larger than 21, but this is not true for the first N-1 numbers which will have a sum of 21 or less.

(In this puzzle, for example, the clue at the top of column 8 means the sum of R1-5C8 > 21 but the sum of R1-4C8 is ≤ 21.)

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 8:30; One party hat (🥳): 18:00. All other solvers earn a 🦕: August Apatodon.

Thomas Hits the GAS (highlight to view): 3:51, 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 and solving video with explanation 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.

Odd Tapa Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
This Sudoku puzzle combines the logic of the shading puzzle genre Tapa to the odd numbers. Can you still solve it?

Odd Tapa Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: It’s All Connected

Author/Opus: This is the 27th 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. Also, all cells with odd numbers must form a Tapa, a single connected wall made out of orthogonally adjacent cells, but without any 2×2 square fully part of the Tapa.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 10:00; One party hat (🥳): 25:00. All other solvers earn a 🦕: August Australodocus.

Thomas Hits the GAS (highlight to view): 4:56, 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 and solving video with explanation 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.

Subsets Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
To get “cracking” in this puzzle you’ll have to think about all the different subsets and what contains what as you move around the grid.

Subsets Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Thunderbolts and Lightning

Author/Opus: This is the 26th 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. For each pair of cages connected by a zigzag line, the set of numbers in the smaller cage must fully appear in the larger cage. Any number on the connecting zigzag line must also be a part of the larger cage but cannot be a part of the smaller cage. Numbers do not repeat within cages.

(For example: The numbers in R4C123 (small cage) and R5C3 (connecting line) must appear in the five-cell cage R67C3+R8C345.)

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:00; One party hat (🥳): 13:00. All other solvers earn a 🦕: August Abysosaurus.

Thomas Hits the GAS (highlight to view): 4:55, 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 and solving video with explanation 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.

Even Sandwich Sudoku by Philip Newman

(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
When a number is surrounded by two even numbers left/right or top/bottom, you’re given a clue to that “sandwich” in this puzzle.

Even Sandwich Sudoku by Philip Newman

PDF

or solve online (using SudokuPad)

Theme: Pattern? What Pattern?

Author/Opus: This is the 25th 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. Also, the clues outside the grid indicate all numbers in that row or column surrounded by even numbers on both sides (”sandwiched”). Clues can be given in any order, and all such numbers are given. If a clue is a ‘–’, then no values in that row or column are sandwiched between two even numbers.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 7:30; One party hat (🥳): 16:00. All other solvers earn a 🦕: August Amargatitanis.

Thomas Hits the GAS (highlight to view): 4:06, 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 and solving video with explanation 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.