PyCon US 2025: Mysterious Sticker Challenge
TLDR >> We brought a sticker-based puzzle to PyCon US 2025. We handed out 300 copies, 150 people engaged with it, and 14 finished the entire puzzle during the conference. More have solved it since then. You can still try. This post does not contain spoilers.
What is the Mother of Exiles?
The Mother of Exiles is a four-part puzzle hunt we created for PyCon US 2025 (Pittsburgh, PA, Friday 05/16/25 to Sunday 05/18/25). It starts with a mysterious sticker and continues on a website whose URL is hidden inside the sticker. It was not endorsed or sponsored by any company or organization; it was built by the community, for the community.
After the conference, we asked participants for feedback, and you can read some of their comments throughout this post.
I loved that this was independent / community organized! and the vibes were great! — Loren
The puzzle structure
The puzzle tells a story, and its theme reveals itself as the player progresses through the first part. The four parts are connected and build upon each other, creating a larger narrative that unfolds as you solve each piece.
While the puzzles are not coding exercises and can be solved without using Python, they are designed so that Python can play a role in solving specific tasks that would be too complicated or annoying to perform by hand.
Throughout all parts, the players check their answers and find additional clues by trying different paths on the site's URL.
When they find the correct answer for a part of the puzzle, they see a message that contains a code word they can submit via email to get credit for their progress.
The solution banner at the end of the puzzle's first part.
Distributing the stickers
We distributed around 300 stickers throughout the three days of the conference. Most attendees found the stickers at the sticker exchange table in the Expo Hall, which we kept stocked, always placing a few at a time, but constantly replenishing them.
The sticker exchange table, with the Mother of Exiles stickers.
We also placed stickers at random places attendees would likely notice: on the bridge connecting the conference center to the hotel, near the WiFi password signs by the couch area, at the badge decoration station, and a few more spots.
[Where did you find the sticker?] open spaces sign up area, Friday morning. Super exciting to find a trail-head in the wild (first time to participate live + in-person). — Ben
[Where did you find the sticker?] In the hallway between the Westin and the conference — Loren
A sticker we left on a bench by the escalators.
From the sticker to the web
To solve the first part of the puzzle, the players have to find the hidden site URL and use the clues in the sticker (image, text, and symbols) to determine the correct path they should visit on the site.
The landing page of the puzzle site.
To accommodate players with various puzzle-solving skills, the site also provides additional hints if users visit specific paths related to the clues in the sticker or the most common incorrect answers.
Puzzles felt very approachable; I found at least two "guardrails" where I had correct/close answer but wrong spot, so I am incredibly appreciative for them. — Ben
But not everything went smoothly. Some players got stuck on the first part and felt frustrated because they weren't sure if they were on the right track. We should have done better at helping newcomers get started.
I’m not sure if that means I solved 1? I left mostly feeling dumb. Or that I was wasting my time. Maybe I’m just not good at puzzles [...] It felt less like play and more like working with an unfamiliar CI/CD system with undocumented behavior. — anonymous
I think if you wanted to make the process more beginner accessible, maybe you have a page for beginners that outlines how to get started and how puzzles work. I think that is what took me the longest time - understanding how I was expected to interact with the website and the sticker. — Leah
But the majority of players who provided feedback found the sticker and puzzle engaging and reported having a great experience.
I really enjoyed completing this puzzle! The design of "discovering" the stickers as an entry point added to the fun of it as an ARG-style puzzle game. — Erik
Open spaces
Part of the experience of solving the puzzle was interacting with other players. To encourage this social aspect, we organized three open space sessions during the conference, one each day, where people could discover the sticker and players could ask questions and work together on the solution.
The Mysterious Sticker open space on Saturday.
Several players mentioned this social aspect as being one of the best parts of the experience, giving them a reason to meet, help, and seek help from fellow attendees.
i had a lot of fun doing the puzzle and enjoyed connecting with others doing the puzzle in the open space! a great way to use python and meet new people. — redshiftzero
I enjoyed the experience and had fun talking to other people about the game just as much as I enjoyed solving it. — Sean
Two players working together on the puzzle.
The test part on the sticker was perfect - but understanding how puzzles work was hard! Once i figured that out, the rest was really neat as was working in groups at the open spaces. — Leah
Having an open space each day allowed for people at similar "stages" to collaborate and, hopefully, network. I would definitely like to see this at future pycons and would encourage using open spaces again as a means of allowing someone to discover the puzzle for themselves, but to then find a group to work together with. — Mike
Social media
Some attendees who noticed the stickers posted on social media during and after the conference.
A toot about the Mother of Exiles sticker.
Web activity
The activity on the site started slow on Friday, but quickly picked up as more people found the stickers and started solving the puzzle. At the end of the three conference days, the site had more than 5,000 page views.
Summary of the activity on the puzzle website for the entire conference.
The final number of unique visitors is not very reliable because our choice of a privacy-focused web analytics provider (Cabin) that does not use cookies or other intrusive tracking techniques, so we could not track returning visitors accurately.
A rough estimate suggests that around 150-175 people engaged with the website during the conference.
Solution codes and the leaderboard
The Mother of Exiles puzzle had four parts. Solving each part revealed a code word that players could submit via email for credit for their progress.
At the end of the three conference days, 14 people had submitted the final solution code, and nine emailed partial solution codes.
The leaderboard on the Mother of Exiles site.
Solution stickers
Players who completed at least one part of the puzzle received a partial solution sticker, and players who completed all four parts received the complete solution sticker.
The solution stickers are special prizes; they were not distributed to anyone else.
The complete solution sticker for the Mother of Exiles puzzle.
After the conference
Some participants shared the puzzle with friends and co-workers after the conference ended. Since then, at least another 10 people have interacted with the site and 8 have submitted the final solution code.
[Where did you find the sticker?] (not at PyCon) someone linked it on a discord — anonymous
[Where did you find the sticker?] A friend gave it to me after they finished it (I've never actually been to PyCon) — Lyra
The Mother of Exiles is still available for anyone to solve, and we will still give solution stickers to anyone who emails us the final solution code for as long as we have stickers.
Lessons learned
The experience of creating and running the Mother of Exiles puzzle was very positive, we had a lot of fun, and we learned many lessons that will help us improve future puzzles.
- We need to provide more help for beginner players, those who are not used to puzzle hunts, especially at the beginning of the experience.
- The social aspect of the puzzle was very important, and we should continue to encourage it in future puzzles. The open space sessions were a great way to facilitate this, and we should consider adding more opportunities for players to meet and collaborate.
- We need to advertise the existence of the puzzle. Some people did not find the sticker until later and did not have a chance to fully experience it.
- Play-testing is crucial. We had a few people test the puzzles, but not enough to rule out all possible issues.
- We need more help! We need to recruit more people to help with the design, development, and running of the puzzle.
What's next?
We are already planning another mystery challenge for PyCon US 2026 in Long Beach, CA! Follow us on Mastodon or Bluesky to stay updated.
We are also looking for anyone interested in helping create next year's puzzle. There are many ways to contribute, regardless of skill level or experience: designing puzzles, play testing, creating graphics, writing text, coding, or helping run the event on-site.
Contact us to learn more!