It’s like dealing with any deep background. Start with what the players and the GM actually need. So for example, I am currently running a Big Rubble campaign with a group of players who have zero pre-existing Glorantha lore. We start with a pretty paper-thin over view of Dragon Pass and Prax – pretty much just what is provided in the Family Background materials. We did a little information about the cults the characters belong to – again just what is in the core book. And then move forward.
In the first session they got introduced to Lanbril thieves and fought some broo and some mercenaries. Later they learned that the mercenaries were actually ogres and started to think there might be some big Chaos thing going on.
Each player soon bought the Lightbringers book because they wanted more stories and information about their cult. A few also got the Sourcebook for the same reason.
Recently they’ve heard whispers of “Gbaji” and “Awakened” and learned these words have a connection with the feared Lunar Empire that until recently ruled the area. A few bought Mythology and read the stories of Arkat and Gbaji, and are now really worried.
In short, let the players and the GM explore things. Don’t worry about esoterica or other continents or even other religions outside of what is likely to affect the game. Let the Second Age start as just being the time of the Empire of the Wyrms Friends and the God Learners. Let your game explore the setting.
Something else – start with a familiar activity and then build from there. Dungeon crawl, investigation, etc.
