Hârndex is an alphabetical, general reference source book for gamemasters using HârnWorld. It includes the following information:

Geographical Entries: Every settlement shown on the Hârn Regional Map is listed, along with many non-map entries. Location entries give the name of the holder, the liege, and approximate population, plus historical and biographical notes as applicable. Populations include nearby villages that owe fealty or taxes directly to the local government. Most other features shown on the Regional Map are also listed, including rivers, lakes, mountain ranges, etc. The grid location of all geographical features is given.

Economic and Guild Entries: The guilds common to Hârn are listed in Hârndex, along with a wealth of information about Hârn's economy.

Religious Entries: The religious information given in the general Hârn article is greatly expanded in Hârndex. Entries can be found on each deity and religious order.

Cultural/Political Entries: All of the cultures and states named on the Cultural-Political Map (in the Hârn article) are described in Hârndex. There is an entry for each barbarian tribe, each kingdom, and most unique creatures.

A Note on this Edition: This third edition of Hârndex is a compilation of the entries from the first and second editions, published in 1983 and 1990 respectively. It also contains material from the Hârnic Dictionary that was published as part of HârnPlayer in 1994. Additional text, illustrations, and maps in this edition have been taken from Hârn material published by Columbia Games between 1983 and 2014.

See also Hârnworld (sold separately).