Rorschach's River: a Collaborative Conundrum
31 December 2025In July 2022, I asked Puzzlers Club whether there would be any interest in writing a big mashup puzzle in an exquisite corpse style. There was. This is that puzzle. Wait, why is it December 2025?
What is this?
It’s a path puzzle. You draw a path that enters the grid at the top and exits at the bottom. Along the way, there are 50 sections, each following a different ruleset. Consecutive sections overlap by a few rows, creating short hybrid sections in between.
I kicked off the puzzle with the first section at the top and then passed it on to the other authors. Each author could only see the section right before theirs (and the list of all rulesets so far, to avoid duplicates). I’m assuming you’re here to solve a puzzle though, so I will write more about the process in a separate post.
How do I solve it?
There’s a few options:
- I think the puzzle is really fun to solve on paper, so I’ve provided printable PDFs.
- If you prefer solving with Penpa+, that is an option, but I’ve had to split the puzzle into 10 parts for performance reasons.
- There are also image versions of the entire puzzle, in case you prefer solving it with image editing software.
All of these include self-contained versions that come with all the rules and example puzzles. But if you want those separately, or want solvable links for the examples, please refer to:
| Rules (PDF) |
|---|
| A4 (2.5M) |
| Letter (2.5M) |
Printable PDFs
The printable versions include all the rules (and the Letter format one also had enough room for shape banks on the side) and are split into three sections per page. Each page ends in an overlap section that is included again at the top of the next page, so you can transfer progress over.
| Printable puzzle (PDF) |
|---|
| A4 (11.4M) |
| Letter (11.3M) |
Penpa+
As mentioned above, the Penpa+ version is split into ten parts, made up of five sections each. You’ll be able to see a greyed out version of an additional section above and below each part. In general, answer check should pop up once you’ve determined the entire path before the greyed out section. This part of the solution will already be given in the next Penpa link. In a couple of cases you might have to solve a little bit of the grey section to complete the path above, in which case you’ll have to transfer that progress over manually.
The intended experience here are the Penpa links that include all the rules and examples, but certain input modes might still cause some amount of lag, depending on your setup. If this is an issue, you can try using the version without rules (and refer to the rules document above), as that greatly reduces the underlying grid size.
| With rules | Without rules |
|---|---|
| Part 1 | Part 1 |
| Part 2 | Part 2 |
| Part 3 | Part 3 |
| Part 4 | Part 4 |
| Part 5 | Part 5 |
| Part 6 | Part 6 |
| Part 7 | Part 7 |
| Part 8 | Part 8 |
| Part 9 | Part 9 |
| Part 10 | Part 10 |
Note that these are using my own fork of Penpa+, which contains a number of improvements that were necessary to make this puzzle feasible in Penpa at all. They will be changed to links to the main fork once my changes have been accepted there and I am not committing to keeping my fork available or stable beyond that point. So if you want to share the puzzle, please don’t link to these Penpas directly and send people to this blog post instead.
Image versions
Finally, you download the entire puzzle as a single image, either as a PNG or SVG. There are three versions here: (a) the full version including rules, examples and shape banks, (b) a version that drops the shape banks, (c) a version containing only the puzzle grid itself.
| Everything | No shape banks | Puzzle only |
|---|---|---|
| PNG (13.0M) | PNG (12.6M) | PNG (5.2M) |
| SVG (5.0M) | SVG (5.1M) | SVG (3.6M) |
Help, I’m stuck!
I don’t want you to get stuck! This puzzle is full of wonderful ideas all the way to the end, and I don’t want people to miss out on those because they hit a roadblock along the way. So I’ve set up a hint page with hints for every section, which hides each hint until you click on it. You can also download PDF versions, but they’re just plaintext, so you might accidentally spoil yourself on later sections if you’re not careful:
| Hints |
|---|
| HTML (recommended) |
| PDF, A4 (2.5M) |
| PDF, Letter (2.5M) |
If these hints aren’t working for you, and you can’t get more bespoke hints on Discord (for example), I encourage you to peek at the solution to get you unstuck and see more of the puzzle:
| Solution |
|---|
| PNG (5.8M) |
| SVG (4.5M) |
Credits
Before I get to all the wonderful folks who wrote a part of this puzzle, I need to shout out a few people who have done a lot more than that:
- One of the bigger Penpa+ improvements for this was implemented by Rever, which saved me a lot of time and also provided enough motivation for me to sort out the remaining improvements myself.
- kays testsolved the final Penpa transcription (and all the example puzzles) and provided a lot of helpful comments on difficulty and sticking points, which informed many of the hints.
- And finally, William Hu and Wessel Strijkstra have been a huge help throughout this project. They’ve helped me test every section as I received them, and then the entire puzzle again at the end. They’ve also wrote a bunch of the example puzzles and helped make sure that all the rules are consistent.
As for the authors of the puzzles themselves, they are listed next to their section in the puzzle grid and also in the rules document, but here is the complete list (in the order of puzzle sections):
Martin Ender (Menderbug), boboquack, Lavaloid, Andy Tockman (tckmn), Michael Tang, Botaku, Eric Fox, Ammar Fathin Sabili, DireKrow, yosh, ft029, Anonymus25, Blaž Urban Gracar, Walker, dohz, Sam Cappleman-Lynes, phenomist, au voleur!, Zachary Barbanell, Teal, Jonah Ostroff, scor, Deusovi, bakpao, wen, kays, Christian König (CJK), lemononmars, Tonta, moeve, David “Taco Dave” Millar, Tom Coward, Rubrica, Craig Kasper, Joseph Howard, Wessel Strijkstra, Emerson Golladay (Rook), Barbitos, Seren✩, djmathman, Elyot Grant, muhorka, IHNN, Stef, Prasanna Seshadri, Jamie Hargrove, jovi_al, wormsofcan, Rever, William Hu (TheGreatEscaper)