It’s not actually hard to write a game that will be fun for a cast of brilliant roleplayers.  Brilliant roleplayers don’t need you to be awesome.  They understand how to make their own fun – from scratch, if necessary.  That’s what makes them brilliant.

The first degree of mastery is this: write a game that’s fun even for dullards and terrified newbies.  

The second degree of mastery is this: write a game that makes it easy for the dullards and the terrified newbies to generate fun for others.