At this moment i have a completely closed forum. I like to make it more open.
Everyone can see all the topic titles, but only registered users can see the whole topic and replies.
And if it is possible only users thats post in a certain topic( introduce yourself) first can reply on all topics
There’s not a way to let people see titles but not the posts.
You can configure a category so that people can post, but not reply, but you can’t configure it such that they can post, but reply only after posting (unless, perhaps you created a badge that was awarded when people posted and then that badge was used to assign people to a group).
I think that what you want is to allow people to read without registration, but require them to get an account to be able to post. Sure you’ll be “giving away” your valuable posts for free, but many people won’t want to register until they know that there is enough content to make it worth their time.
Oh. Sorry. I missed that. That’d require a plugin. Or be impossible.
Discourse encourages people to register with messages about how it’ll remember what they’ve read and such. In my experience, even being able to “like” stuff that I’ve seen is impetus to log in. I will almost never log in to a site where I can’t see anything.
The first will show the categories and their topics, but access to the topics is still restricted.
The latter lets you show the private categories alongside those a user can normally access, but they cannot see topics or their contents.
If you’re a hosted customer I would recommend the latter as it’s a theme component and a straightforward install. If not then consider the plugin, but only if the topic titles in your private categories aren’t sensitive.