Warchon (2002)

From the game's description:

This new concept in gaming can be played anywhere and uses two main components. A book that replaces hex maps and game boards (and includes the rules and scenarios to boot). And play marks (i.e. book markers) for two armies to do battle as they move through the pages of the book.
Nothing else is needed, not dice, not even a playing surface!

In this Playmark Book Game (PBG) players become Warchons - battlelords fighting for domination of the continent of Sygillis.

You'll build and control the forces of the holy warriors of the Celestine Order or the foul creatures of the Azuthkan Horde. Cast spells, combat in various terrain and survive random events, all while vying for the title of Grand Warchon!