CS50 Lunch

RSVP at if you’d like to join classmates and staff for CS50 Lunch this 2023-10-06T13:15:00-04:00/2023-10-06T14:30:00-04:00!

Live Stream

Ready Player 50

Ready Player 50

Like to learn more about artificial intelligence (AI), large language models (LLMs), and prompt engineering? Register for Ready Player 50 at

The CS50 Duck has a secret. Can you convince it to reveal its secret? Join CS50 and for a challenge in which you’ll face none other than CS50’s duck debugger, aka ddb. But be warned: each time you crack the code, the CS50 Duck will “level up” and become more protective.

Along the way, learn about prompt engineering and, in turn, prompt-injection attacks, which can be a problem with large language models (LLMs). This challenge is a new version of the world-famous prompt-injection game Gandalf, designed specifically for CS50.

Starts 00:00 on Friday, September 29, 2023, in your own time zone. Ends 23:59 on Monday, October 2, 2023, in your own time zone. Teams of size 2, 3, or 4 are encouraged, but you may form larger teams of reasonable size. Open to anyone online, whether taking CS50 or not, including friends and family back home!