I think maybe 20 or 21?
Pretty much what is says on the tin! Basically it's What age do you think the above OC is? but OOC.
You can make assumptions based on pretty much what you want, the user's icon, their characters (and their average age, sometimes it's a clue!), their way of writing, etc. Just don't cheat (by looking at the above user's profile unless they say it's okay to, or by looking at the previous replies, for example), and please stay respectful when giving an explanation!
To keep this thread challenging and fun, please do not make vague assumptions (such as "14-18", "early twenties", etc.), since I think most TH members are between 13 and 30. Always try a specific number or two! Thank you ~