Tuesday, July 13, 2021

Puzzle No 167: Regional Necklace Tapa Loop

This Puzzle was created during the speed setting contest over Cracking The Cryptic discord server within a time limit of 60 + (30 extended) min.

The goal was to add our own rules to the pre-defined ruleset (Necklace Rules) and create a puzzle within the time limit. Almost at the end had a unique-ness issue and had to place an unsymmetric clue to resolve it but overall happy with the puzzle.


Necklace Rules:

1) Shade some cells in the grid such that all shaded cells form one orthogonally connected region, and no 2x2 region is completely shaded.

2) Draw an orthogonally connected, nonintersecting loop through some cells in the grid such that the loop path alternates between shaded and unshaded cells (i.e. before and after every shaded cell on the loop is an unshaded cell and vice versa).

Additional Rules:

3) Number of turns in each region must be the same and is to be determined by the solver.

4) Loop can pass through Number cells but Numbers cannot be Shaded.

5) Number clues are regular Tapa clues.

6) Loop must pass through given circles.

Penpa+: Online Solving


Sunday, June 27, 2021

Puzzle No 166: Surplus Sudoku

This Puzzle was created during the speed setting contest over Cracking The Cryptic discord server within a time limit of 45 min.


Insert a number in the indicated range into each cell so that no number repeats in any row or column. Some regions appear with more cells than there are numbers in the indicated range. Some number(s) repeat in these regions, but all numbers in the indicated range must appear at least once within each of these regions.

Penpa+: Online Solving

Puzzle:  Range (1-6)

Friday, June 25, 2021

Puzzle No 165: Heyawake

This Puzzle was created during the speed setting contest over Cracking The Cryptic discord server within a time limit of 90 min.

Host provided two custom boards (Hash and Ring) shaped. Here are the links if you want to create one.

1. Hashtag

2. Coin with hole

More importantly, finally, this entry made me win the contest :)


Paint some cells black. Black cells are not allowed to touch each other on the sides. The remaining white area has to be connected. The white area can't span over two consecutive boundaries in a single row or column. The numbers in the rooms indicate how many cells are to be painted black.

Penpa+: Online Solving


Puzzle No 164: Tapa Palindrome

This Puzzle was created during the speed setting contest over Cracking The Cryptic discord server within a time limit of 60 min.


Shade some empty cells black to create a single connected wall. Numbers in a cell indicate the length of consecutive shaded blocks in the neighboring cells. If there is more than one number in a cell, then there must be at least one white (unshaded) cell between the black cell groups. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid.

Additionally, the grey lines must be palindrome in terms of shaded/unshaded cells. 

Penpa+: Online Solving


Puzzle No 163: Yajilin Twist

This puzzle was entered into Logic Showcase #25 (Ubnique Tilings).

The challenge was to create a logic puzzle using a grid-based on any tiling other than the standard square tiling.


Blacken some white cells and then draw a single closed loop (without intersections or crossings) through all remaining white cells. Blackened cells cannot share an edge with each other. Some cells are outlined and in gray and cannot be part of the loop. Numbered arrows in such cells indicate the total number of blackened cells that exist in that direction in the grid.

Additionally, Numbered arrows also indicate the total number of cells where the loop turns. Loop cannot cross on given edges.

Theme: Ones and Twos

Penpa+: Online Solving


Tuesday, June 1, 2021

Puzzle No 162: Double Thermo Sudoku

This Sudoku was created in an attempt to invent a new variant. Although later I was notified that a similar (but not exact) variant already appeared on the Cracking The Cryptic youtube channel. Anyways this should be still fun to solve and explore.


-Normal sudoku rules apply: In a row, column, or box, the digits 1-9 have to appear exactly once.

-Thermos: Along the thermos, divide the numbers as a group of 2 digit numbers and these two-digit numbers must increase from the bulb to the end. 2 digit numbers are read in the direction from the bulb to the end.

Theme: 33

Difficulty: Medium

Penpa+: Online Solving


Puzzle No 161: Pentominous

This Puzzle I created while recording a video on PenpaPlus Channel. It's easy but fun and teaches you the basic fundamental rules of the Pentominous puzzle genre.


Divide the grid into pentominoes (five-cell regions) so that no two pentominoes of the same shape (including rotations/reflections) share an edge. A cell with a letter in it must be part of the pentomino shape normally associated with that letter. An inventory of pentominoes is given below the puzzle but not all shapes must be used.

Difficulty: Easy

Penpa+: Online Solving


Puzzle No 160: Hybrid Sudoku

I created this Sudoku to exploit an interesting discovery I found in a "No Even Neighbor Sudoku".

I have also published this Sudoku on the LMD website, if you would like to go over there and provide your rating, I would really appreciate it.


1. Normal classic rules apply. i.e. Place numbers in the grid such that each row, column, and 3*3 box contain the numbers 1-9.

2. Thermo rules apply. i.e. Some thermometer shapes are in the grid, digits must be strictly increasing from the round bulb to the flat end.

3. Little Killer rules apply. i.e. Outside clues are the sum of digits along the pointed arrow direction, digits may repeat as long as classic rules are satisfied.

4. No Even Neighbor rules apply. i.e. No Two Even digits can be orthogonal to each other. (i.e. they can't share an edge)

Difficulty: Hard

Penpa+: Online Solving

Trick/Hint: Spoiler