[1] The contents of the folio include Hârn is a low-fantasy setting with a minimum of magic, based largely on Norman England, with the addition of some fantasy elements provided by dwarves, elves and orcs.

Instead, gamemasters of the time were expected to adapt the Hârn world to an existing rules system such as Advanced Dungeons & Dragons or RuneQuest.

[5] Over the next 30 years, Columbia produced dozens of source books about Hârn that delve more deeply into regional characteristics, culture, economics, and religion.

Due to the lack of ready-made adventures or adventure hooks, Moore recommended the game system for experienced gamemasters "who don't mind using a largely pre-fabricated universe", but warned "It is not a good idea to purchase Harn if you like to extensively alter game material unless you don't mind spending money."

Swan concluded by giving this product a rating of 3 out of 4, saying "Players expecting a surplus of magic and monsters will be disappointed, but those looking for serious, intelligent adventures can find plenty of them in Harn.