Quote:skill leveling come from completing achievements which are unique challenges with differing difficulty and experience rewards.
This line is a simple abstract line that will take lots of work because the application of this simple statement is the bulk of a game. This design will is good, but to implement it at a plausible rate is difficult. That's why creating an RPG is better than an MMORPG for a simple statement but complex application.
Alpha_ProgDes, I will suggest that since we have a party of 3, that the "special" experience should be unique to the individual character while the general experience is together for the party.
Special experience is the accomplishments that the characters can possibly do.
General experience is the basic experience the characters get when they kill a monster.
Why give the special experience uniquely to the characters? This is so the player can create unique party roles for the characters.