Join us for the second-annual CS50x Puzzle Day in the UK, this time at Oxford!

CS50 is back in the United Kingdom! Join us at the University of Oxford on Friday, November 6, 2026, 5pm–10pm, for a CS50x Puzzle Day in collaboration with Oxford Lifelong Learning, with Professor David J. Malan (https://cs.harvard.edu/malan/) from Harvard, Professor Daniel Wilson from Oxford, Professor Nicholas Day from Oxford, and Professor Tom Crawford from Oxford (and Cambridge and Tom Rocks Maths).

CS50x Puzzle Day is an opportunity to collaborate on teams of 2, 3, and 4 to solve a packet of puzzles (i.e., logic problems). Among the event’s goals is to send a message that computer science is more about problem-solving than it is about, say, programming. Puzzles are not programming challenges. No prior CS or programming experience needed, just logic and smarts! No team? No problem! We will help teams form at the event. Tickets on sale until 4pm on November 4, 2026.

Open to anyone who is:

Taking or teaching (or has already taken or taught) CS50x or any of CS50's other courses

Local (or able to travel) to Oxford, United Kingdom

Schedule

5:00pm: Check in, get your CS50 swag and some pizza!

6pm: Puzzle solving

9pm: Solutions revealed

What to Bring

Government-issued photo ID (no admittance without one)

Eventbrite ticket

Laptop with charger or phone (for using internet)

Pen/pencil

Scratch paper

Get ready for the second-ever CS50x Puzzle Day at Oxford! This is your chance to meet and collaborate with classmates on a packet of puzzles (i.e., logic problems). Whether you're a coding pro or just getting started, this event promises a fun and inspiring experience. Don't miss out—register now and be part of this historic event! Quack.

— said the CS50 Duck at cs50.ai (https://cs50.ai)

Space is limited. Pizza and drinks will be served.

No preparation (or prior background or experience of any sort!) is expected. But you might find it helpful to peruse CS50x Puzzle Day 2025's puzzles (https://cdn.cs50.net/2025/x/events/puzzles/puzzles.pdf) and walkthroughs of solutions (https://www.youtube.com/playlist?list=PLhQjrBD2T382YYIbR35WxbPkiRkj2veMs)!

If ticket price would prevent you from attending, email outreach@cs50.harvard.edu.

If you are a student at Oxford (whether taking CS50 or not), email outreach@cs50.harvard.edu for a discount code from your ox.ac.uk address.

Past Quotes

A good activity to do with friends!

Difficult, Challenging, but most of all, Memorable!

Extremely fun but mind boggling at the same time

Great fun, and I think I even have a few non-grey hairs left!

Had the best online experience of my life. Got a chance to get to know many people from different countries. Absolutely loved the experience.

I can describe CS50 Puzzle Day in one word as Awesome. It’s just wonderful, I feel so confident after making new friends from other parts of the world, solving puzzles with them which improved my team coordinating skills. I have learned so much from the competition and my new friends and I would love to take part in this competition every year.

It was a lot of fun and a great way to use your mind in a different way than you usually do day to day.

It’s brainwreckingly good!

Description supplied by the event organiser.