What is HackMerlin?
HackMerlin is a short puzzle game about outsmarting a chatbot. Merlin, an AI wizard, has a secret word and has been told not to share it. Your job is to ask questions that get him to slip up anyway. Once you think you know the word, you submit it and move to the next level, where Merlin is better protected.
There are seven levels. Early ones fall to simple tricks, while later levels add output filtering and a second AI that checks Merlin's answers, so you have to get more creative with spelling, riddles and indirect hints. It is in the same family as Lakera's Gandalf and has been shared on Reddit, X and YouTube walkthroughs. There is a leaderboard, and the site describes the goal as experiencing the limits of large language models first-hand.
What You Can Do
- Chat with Merlin to coax out his secret word
- Climb seven increasingly difficult levels
- Face filters and AI checkers in later levels
- Submit your guesses and track progress
- Compare results on a leaderboard
How to Play HackMerlin
- Open HackMerlin.
- Ask Merlin a question that might reveal the password.
- Enter the secret word when you think you have it.
- Move up a level and try a sneakier approach.
Is HackMerlin Free?
HackMerlin is free to play with no login and no pricing on the site.
Who Will Enjoy It?
- Players who enjoyed the original Gandalf game
- Developers learning about prompt injection
- Puzzle fans who like word tricks
- Students curious about AI safety
Websites Like HackMerlin
- Gandalf: Agent Breaker: A bigger follow-up with ten realistic AI apps to break.
- Goody-2: A chatbot that refuses almost everything, can you get an answer?
- The Password Game: A different kind of password puzzle, with absurd rules.
Frequently Asked Questions
Is HackMerlin free?
Yes. It is free with no account.
How many levels does HackMerlin have?
There are seven levels, each with stronger defences.
Is HackMerlin like Gandalf?
Yes. Both ask you to trick an AI into revealing a password, which teaches how prompt injection works.