Subtitled: "A History and Guide to Role-Playing Games"
Released in 1991, Heroic Worlds makes a heroic attempt to catalog every RPG in print as of that time. He does a very good job overall. He misses some of the smaller independent press releases, and includes at least one item that was never released, but for the most part it's an excellent resource. It's organized by genre.
Schick is close to neutral on many items, but he has his favorites and his dislikes, and lets you know about them. In fact, each chapter opens with his list of what he considers the best in the featured genre.
In addition to the encyclopedic content, the book contains a chapter on the history of roleplaying games. There are also a number of guest articles about the early days of creating and publishing written by:
David L. Arneson
N. Robin Crossby
E. Gary Gygax
Paul A. Jaquays
Ken St. Andre
Michael A. Stackpole
B. Dennis Sustare
No unique interior artwork; art extracts from various games are "used by permission" and individually credited.