Hi. With the trouble we seem to be receiving on the MUGEN Database at the moment, I wanted to ask this. Is there a way to change what a user group can do? Say to prevent Wikia Contributors from creating pages (still allowing them to edit them). This would cut down on our problems by a HUGE amount.
If a wiki is receiving heavy amounts of vandalism, you can get a temporary protect site (disallowing anonymous users from editing). In the long term, the Abuse Filter extension is the better bet. The AbuseFilter is an extension that allows you to set conditions. If those conditions are met, you can choose what happens then (usually stopping the edit from happening). Special:Contact to talk to staff about either.
This is an available option, but in my experience it doesn't really stop vandalism for long. It's more of a short-term solution to an acute vandalism problem, especially because of the large percentage of recent new pages that have been kept that are by non-logged in users - I wouldn't recommend this as a good solution.
What kinds of vandalism problems are you having? As TK has said, AbuseFilter might fit your needs better, as you can set up tags for the kinds of edits that might be a problem, and even block certain edit patterns as it suits you.
Perhaps not recent-recently, but around Christmas last year, we had massive floods of unregistered users creating random (and sometimes offensive) pages - to prevent this from happening again, if there was an option to change what user groups can do on the wiki, I would make it so that unregistered user cannot create pages.