RPG campaigns are great fun, and a lot of work is put into plotting and characterization, rather like fiction writing, but can any of it be used in actual fiction works? Perhaps some of it can, if avoiding common pitfalls in translating an RPG to novel:
1. Class stereotypes
Is the fighter a one dimensional tough guy? Try some twists like Joss Whedon did with Jayne on Firefly, or George R.R. Martin creating Brienne. Combine some of the classes together—what if a rogue was also a paladin? Can’t work? How do you know until you try?
2. Combat stagnates
RPGs do not cover a blow by blow of the battle, and despite all sorts of powers, there are definite progressions that tend to come up in combat. To make it more exciting, turn instead to historical research of actual battles, rather than relying on dice and statistics. That being said, there is something to be learned from a confident fighter who suddenly rolls horribly and is taken out when he shouldn’t have been. It can make a great plot twist!
3. All about the loot
Characters have complex motivations, even in an RPG, but ultimately you are very interested in picking up new pieces of armor, weapons, potions, and treasure. This can hamper a novel’s story, because in real life, while there will always be those only out for stuff, we are more complicated than that. Academics are almost hit by cars when they walk into the street reading a book, and people might be so driven by a love of baseball that they give up the finer things in life to afford tickets. If characters run around trying to get stuff all the time, it becomes a boring read. Make sure there is a balance of acquiring important gear for the quest, and actual storytelling. Think of Lord of the Rings—other than an epic loot drop from Galadriel, there isn’t a lot of gear hunting going on.