Though all of the campaign materials are system-neutral, HârnMaster is a game system designed by Hârn's creators with the setting in mind. Columbia Games, Inc. has produced three editions under this name, and Keléstia Productions Ltd. calls their presentation HârnMaster Gold. All of them are mostly compatible with one another.
It is also devilishly hard to categorize and sort these works. Each module within HârnMaster 3 (if that's where they should go) seems to have launched its own branch of fanon, which makes for an unwieldy listing here. Many contain not just game system rules but setting information too, which also argues for splitting this section up. But then what would remain? Multiply over the editions, and it gets worse.
So the present editor has made decisions that will hopefully be adequately explained if not so well thought out. The Religion series, being a stand-alone entity though containing some HârnMaster rituals and skills, has drawn fanon concerning rituals. The Magic section has been treated the same way, partly for a sense of consistency with religion but mostly due to the unruly tangle of fanon accompanying it. The canon works, however—HârnMaster Magic and HârnMaster Religion—have been Solomonically listed in both places because they have “HârnMaster” in the titles. NPCs have been hived off since they have strong setting content, and PC records have been assigned to the Game aids section for space considerations.
What remains is canon and fanon relating to general rules, bestiary articles, and articles seemingly classed with HârnManor and Pilots' Almanac. BattleLust materials are here as well, seeming to be close enough. The articles have mostly been assigned to HârnMaster 3, unless they refer to other versions or specify their use with any version. HârnMaster Gold has been placed at the top if the list not due to any preference on the part of the present editor but just so that it doesn't get swamped by the rest of the material and relegated to the bottom of the page. Indeed, the present editor has not played any of these systems, and is solely responsible for any errors in the assignments made.