Gandalf A few months ago someone sent me the “Gandalf” prompt injection challenge and I finally sat down to go through it. Complete with creepy AI generated “Gandalfs”(??), it’s an accessible CTF that people can even do from their phones… in bed… like me. I found this to be exceptionally fun because they are novel techniques and people come to their own, often unique solutions a variety of ways. To help get the creative juices flowing I read a few blog posts about prompt injection and went form there.