I've begun work on the spec for the Story Engine. This is a somewhat complicated database-driven system for generating missions/quests/tasks/whatever you want to call them.

The actual mission generator is complex. The plan at this point is that there are no scripted missions. Every mission is assembled algorithmically from a database of plot elements. No two are ever alike.

But there is also a story generator. The story is the aggregate of all your missions. The story generator filters possible missions according to your record of past missions and your progress through your career. So early in the game, you're getting simple missions. By the end, you're involved in intrigues that bring countries to war.

Along the way, the story generator is keeping track of the NPCs you've met in the various missions. They aren't disposable. Each becomes a bot who has its own NPC career in the game world. The villain you faced in your very first mission may well dog you all your days, ambushing you when you least expect it or conspiring with your allies to betray you.