If your 13 year old is mature and into it, just say they’re 14. They don’t card. I took my DS when he was 12 and 13 frequently. But he LOVED it and was able to participate as well as the 20 somethings in the class with us. If your kid has even a touch of inattentiveness or can’t follow instructions, then not a match. But the classes we took were all great!