HârnWorld

Columbia's HârnWorld Series :

- The company product web page.
Harn Files :

- House rules, character descriptions, and links.
Harn Religion Team :

- Details of all Harnic religions. Maintained by a team of Harn fans across the world, including many who helped work on the HarnMaster Religion supplement.
HârnForum :

- The official online Hârn discussion forum.
HârnPage :

- Official fan page for HârnWorld, featuring new rules and campaign background. Accepts submissions.
Lýthia.com :

- A portal site to the world of Hârn. Features a FAQ, download, and Fan Projects.
The Schylla & Charibdis Pax Tharda Home Page :

- A guide to the Thardic Republic.
UserMode:HarnWorld :

- Features two adventures, and a new players' guide.
WarFlail's Armoury :

- Features house rule and a database of Hârn fan-sites.
WebRing: harnring :

- Group of interlinked sites also known as the "Harnworld and Harnmaster Ring".