Creative Leads are the driving force behind story elements, characters, plot, etc. The Lead Designer can be the Creative Lead - they are not mutually exclusive - but separate people might hold the positions as well. For example, George Ziets was the Creative Lead on MotB and Kevin Saunders was the Lead Designer. A project might also have a Lead Systems Designer who is to gameplay systems what the Creative Lead is to story and characters. There is sometimes a Lead Level Designer as well, depending on the requirements of the project.