So I became Major last night and it says I gained access to the tactician badge but I cannot choose the tactician class. I still only have three classes and there is nothing after the engineer class. Do I need to do something? What's going on here?

Strange, are you sure the game you are in allows the Tact class to be used?

oooooh. I didn't know some games do not allow certain classes. That makes a lot of sense. Thanks.