Here's a list of different places you can chat about this series of games. We're a bit divided, but the fans are out there!
!stauf_mansion@lemmy.mods4ever.com - This Lemmy community, you're here right now! If you need a Lemmy account then go here and make the account. (Sorry, my server is too weak!) If you already have a Mastodon account (and you're feeling brave/technical) then you can put @stauf_mansion@lemmy.mods4ever.com into the search box there and follow that account.
https://discord.gg/Hss5cJg - Stauf's Mansion Discord. Pretty active with a good number of fans. ALSO HAS Stream Detective so you can find people streaming these games on Twitch! Very fun to watch people fumble through the puzzles for the first time and chat with them, just be careful with backseating. Make sure you assign yourself the roles to get notifications for Stream Detective, ask in there if you need help.
https://www.reddit.com/r/7thguest/ - Reddit community. Not very active, but with a good post or crosspost there could be people from outside the subreddit finding it.
https://www.facebook.com/groups/the13thdoll - Facebook group. Lots of fans for all the games here, very active.
https://mastodon.social/tags/the7thguest - Mastodon hashtag #the7thguest, you can follow hashtags on Mastodon so they automatically show up on your home feed, very handy! Also check the hashtags for #the7thguestvr, #the11thhour, and #the13thdoll and whatever else you want.
https://www.gog.com/forum/the_7th_guest_series - GOG Forum. Mostly tech support questions but there are a lot of fans there.
https://www.gog.com/forum/the_13th_doll_a_fan_game_of_the_7th_guest - again a GOG Forum but for The 13th Doll. Still mostly tech support questions.
https://www.twitch.tv/search?term=the%207th%20guest - Twitch categories so you can watch people playing the games live and chat with them (just be careful with backseating). Open each one and click Follow to add the game to your followed categories list. But honestly you're better off joining the Discord and using the Stream Detective inside there.
https://twitter.com/hashtag/The7thGuest?f=live - Twitter hashtag #the7thguest. Unfortunately you can't follow a hashtag on Twitter, so you gotta just check it manually. Also check hashtags for #the7thguestvr, #the11thhour (although there's some noise in there), #the13thdoll, and any other game you want. (Make sure to switch to the "Latest" tab instead of "Top")
Any other places with fans of the series? Let me know! I'm mostly hanging out here and in Discord, but I'll probably see you if you post to any of the others!