An IP-free version of Chapter Six, "Advancement," from The Dresden Files Roleplaying Game, Volume 1: Your Story, made freely available on the faterpg.com website.
Characters are not static objects—they grow and develop over time, evolving in response to the conflicts they face during the game and the choices they make. Settings are similar—but they grow and develop in response to the successes and failures of the various characters. The rate at which both characters and settings grow and change is measured in milestones.
Milestones & Characters
Milestones are moments in the game where something has happened to justify some kind of advancement. Milestones largely occur according to the GM's discretion, and the frequency of their occurrence will do a lot to establish the overall tone and feel of a campaign—frequent milestones allow the characters to grow rapidly and give a sort of "epic" feel to the campaign as the opposition scales in response; infrequent milestones make things feel more grounded and established.
Milestones fall into three categories—minor, significant, and major. There are some guidelines for when each happens, along with what characters can do during each type of milestone.