Core sourcebook for the OGL game. Book includes a very nice map of Magnamund.
From the back cover:
"Lone Wolf, The Roleplaying Game is an entire sourcebook and roleplaying game encompassed within a single tome. Every rule and roleplaying suggestion is included in the spirit of the original Lone Wolf series, updated to OGL rules and expanded to incorporate both North and South Magnamund.
Over 100 pages are dedicated to the Gazetteer and Bestiary sections, with detailed descriptions of the many realms, races and monsters that make up Magnamund. Notes on cultures, encounters and the inevitable dangers of the land will be at your fingertips. Want to travel into the Jungle of Horrors? This guide will let you know what plants are edible and which ones might try to eat you instead and discover why you should stock up on your laumspur potions before taking a trip to Ruel. Statistics for dozens of terrible beasts and vile henchmen are given, to throw at those foolish enough to oppose the rise of the Darklords. From skulking Giaks to the raging might of the Mawtaw, these foes will pose quite a challenge for anyone determined to play a hero in a world destined to fall before the might of Helgedad and its shadowy hordes."
- Lone Wolf: The Roleplaying Game