MyBB Community Forums

is it possible to set up forum permissions so guests (possibly a different user group as well) can view the titles of threads, but not read the thread unless they're signed in and/or in a certain user group?

You could use the plugin below. May be outdated so install it and check if you encounter any problem.

Link: http://mods.mybb.com/view/guest-s-can-t-view-threads

Alternate Plugin: http://mods.mybb.com/view/member-groups-...-threads-2