From the publisher's website:
For the first time, you can now collect the RuneQuest main rulebook, the Companion and Monsters as one mighty tome! This book contains all the essential information the RuneQuest Games Master (or dedicated player) needs to adventure in any fantasy setting, be it Glorantha or one of your own devising.
With the information within fully integrated into one cohesive book, allowing you to review the Rune Magic, Divine Magic and Sorcery options for your character, side-by-side. With enough creatures to populate an entire continent and all the core rules, RuneQuest Deluxe is your entry to one of the longest running and most loved roleplaying games.