Author Archives: rob

Puzzle 172: Ring-ring

Here’s a little Ring-ring puzzle I made when testing that a bug in pzprjs was really fixed. [] [].

An unsolved 9x9 Ring-ring grid.Rules Fill the empty cells of the grid by drawing rectangles that consist of horizontal and vertical lines between cell centers. The sides of different rectangles may intersect but not overlap. Rectangles can’t touch otherwise; in particular, they can’t touch by a corner.

Announcing, a.k.a. Puzzle 169: Angle Loop

Here’s another Angle Loop, and you can solve it on the new

(You might want to try the example first: is a clone/fork of the excellent, a puzzle solving site and applet built by Daisuke Kobayashi. It seems the author has moved on, so when I wanted pzv support for some angle loops of mine, I decided to go ahead and fork the project. I’m hoping will be updated again and would be happy for my changes to make it upstream! I’ll be putting effort into separating the changes useful for upstream from site-specific changes.

For most puzzle types you can move them from one site to the other by switching between and in the URLs.


There are three new puzzle types: Besides Angle Loop, there is Heyawacky which slightly generalizes Heyawake by allowing non-rectangular rules. And Nurimisaki is a type that was quite popular on the Japanese puzzle twitter this year, where it was shared using the Kurotto applet. I hope to post some example puzzles for the other types soon. The additions compared to are shown in the “Added puzzles” tab in the type list.

The second major change is that… links? come with “rich link preview”, or whatever you want to call it.


I intend to keep updating this with new puzzle types and fixes as I need them, but I’m also happy to accept contributions. I would be particularly grateful for help in keeping the project Japanese: Some of the changes I’ve made so far are lacking Japanese translations, so please let me know if you can help with that.

If you have a bug report or want to submit some changes, head on over to github: robx/pzpr-puzzlink for the site, or more likely robx/pzprjs for the puzzle applet itself.

Puzzle 167: Dual loop

Here’s a new loop type. You can solve and check your answer over here. (Let me know if that works for you and is useful, very much work in progress.)

In other things:

  • I’ve worked on puzzle-draw a bit; there’s now an incomplete and experimental more generic input format, which should eventually allow you to draw graphics for non-hardcoded puzzle types. Including doing things like using other symbols instead of numbers where number clues are currently expected.
  • Be sure to take part in the Puzzle Grand Prix next weekend, authored by Jonas Gleim and me. There should be some nice puzzles in there. Check out the instruction booklet.
  • We’ve published a puzzle book via the German Logic Masters, with a chapter of Minesweeper puzzles by myself. There’s a number of prominent constructors involved! (It’s not really being marketed to expert puzzlers, which I suppose explains that the publisher doesn’t even bother to note the involvement of serial world champion Ulrich Voigt.) It’s claimed to be available already, though there’s some information it won’t ship before March. Have a look inside at or check it out at or

Finally here’s the puzzle:Rules Draw two loops that consist of horizontal and vertical segments. One loop goes along the grid lines, while the other loop goes from cell center to cell center. Clues indicate how many of the (up to) four adjacent edges have an intersection of both loops.


New release of puzzle-draw, with new web frontend

I’ve polished up the mess that is puzzle-draw a bit. With the latest release, you should be able to download working binaries for Linux and Mac. More importantly, I put together an ugly but fully functional web frontend that you can use:

Depending on how well the server holds up, you can use it to edit puzzles interactively, and download the graphics in different formats.

It’s still a huge mess of various undocumented puzzle formats, but the examples should give you an idea of what’s possible. Let me know if you have problems, here or on github. In particular, I’m generally always happy to add common puzzle types, as long as someone has a need for them.