There is actually an add-on for vBulletin that will do this.
This mod is an addon to the Inferno Quiz System You must have that mod installed and working to use this.
What it does: It requires users to achieve a minimum score on a specified quiz to post in a forum.
Example: You have a PHP discusssion forum for advanced coders. You don't want novices bothering your members with trivial questions. So, you require anybody who wishes to post in that forum to achieve a minimum score of 70% on an advance PHP quiz that you created using Inferno Quiz.
How to install it: Import the Product. Done. No template edits, nothing else to do.
How to use it: In your forum manager, edit the forum(s) you wish this to use this mod for. Enter a Quiz ID and the minimum acceptable score. Save the forum. You're done.
You can easily require users to pass different quizzes to be able to post in different forums. If a user has not taken the quiz, he is directed to do so. If he has failed the quiz, he sees an error message.
