Sorry if this has been explained somewhere before, I browsed through these forums and other searches and haven't found a definitive answer. I played RQ briefly (think it was made by Avalon Hill at the time) back in the 80s - but we moved to WFRP and never really went back to other fantasy games/settings.
I've just purchased the RuneQuest - Roleplaying in Glorantha - Slipcase Set, I understand that is the rule set and the Glorantha setting - but I'm confused how that works with the 2 other products I'm looking at:
The Glorantha Sourcebook - Hardcover
The Guide to Glorantha (slipcase set)
What do these 2 other products add to what I've already purchased in the Slipcase Set?