Chaosium's RuneQuest and the world of Glorantha have a long and storied history; being over 40 years old with numerous editions, I was honored to be the lead designer and set the tone for their latest edition.
Unlike many fantasy roleplaying games, RuneQuest is inspired by Eurasian Bronze and Iron age history as opposed to Medieval or Renaissance Europe so we wanted the design elements to reflect that. We chose geometric patterns and graphical elements that look like bas-reliefs to help convey that feel.
Because RuneQuest has been around for so long, the art library available is vast and includes many different styles. To help unify these different pieces, I chose to use muted watercolor strokes as a background for images and watercolor brushes to fade out many of the larger pieces; this also served as a way to really integrate text and image and avoid a boring, textbook-like presentation.