I just finished running the Extraction mission and had a question, are Librarians able to use multiple psychic powers in one turn? My player who is using a Librarian wanted to and I told him he could so long as he took a -20 penalty on both focus power tests and so long as both powers only used a half action. Was I wrong to allow this? I can't seem to find the rules for using multiple powers in one turn in the book.

The rule that wasn't being used is that a character can only perform a specific action once per turn. In other words, after he uses the "Focus Power" action, he can't do it again (even though it might be a half action). So you can't do two standard attack actions in the same round. This is also why the move action specifically states you can do it twice, or that we refer to a "full move" and "half move".

If you want to keep you're own mechanics, -20 on continued actions of the same type seems fair though, a good way to encourage players to do other stuff with their actions.

Thank you, I thought that was what the rule just wanted to clarify.

Ya I think you made a fair ruleing there, change the rules how ever you like just stay consistant that is my #1 rule. Book is just a guidline and I let my players know that on day 1.