Class expertise is a measure of how you've progressed within your class and
modifies a myriad of different aspects of how your class performs in the world. 

   For example; class expertise is rolled against an opponents saves to determine
if a spell is saved or not. 

   Each class has a base expertise, most commonly 3, and a primary stat. The base
goes up every 6 levels - so if your base is 3 and you are level 6, your new base is
now 6. It goes up to 9 at 12 and 12 at 18. 

   Your primary stat adds a bonus to your expertise for every 2 over stats over 13,
   i.e. +1 for having a 15 in your primary stat.

   Your expertise can then be calculated by:

      base + level / 2 + stat bonus

   So a level 10 mage with 18 perception would have a class expertise rating of

      6 + 5 + 2 for a total of 13.
such as "spell" or "MUD Basics"
# 418 topics