I get some interesting search results trawling the internet for CYOA books for adults... not what I am looking for! I have a man-child in residence who would like a CYOA adventure book for Christmas -- and who can blame him, they were awesome -- but written for adults. Anyone know of any good ones? The downside is that it must be a real, paper & ink book. The upside is that he likes SciFi & Fantasy. There must be some out there, surely? Anyone?
If he's a man-child, why does he want one aimed at adults? I'm sure the Peter Jackson / Ian Livinstone ones from the 80s would suit him. You can't say they're aimed at adults as such, but nor can you say they're specifically aimed at children either. However... http://www.amazon.com/dp/R4HM34C9FA/?tag=writingfor07a-20 https://www.goodreads.com/list/show/18733.Adult_Choose_Your_Own_Adventure_Books https://www.reddit.com/r/AdultCyoaBooks
Ha... well I guess his reading age is different these days, even if his interests aren't! I've not seen the Jackson/Livingstone ones, I'll have a look. These are the ones I know from being a kid: https://en.wikipedia.org/wiki/Choose_Your_Own_Adventure Cheers for the links too
Gotta recommend Ryan North's To Be or Not to Be, which is a CYOA version of "Hamlet". Not really in either of the genres you specified, but hilarious and well-written.
Although it's not really a book you can give as a gift, you might want to look up Twine. It's an engine that allows people to create their own choose-your-own-adventure style stories in HTML, with little to no knowledge of coding. There's a thriving community around it, and many of the stories they write are available for free on the internet. As I day, it won't make a gift, but it might be of interest to your friend.
I can't imagine why, but the links to the sample games on the twinery.org website are being blocked as malware by my Avire AV software. Just a warning.