Blackmoor began as a development of David Wesely's "Braunstein" games following Duane Jenkins' Brownstone (Old West) variant and Arneson's own wargaming sessions, into which he had begun to introduce fantasy elements.

[1] Initially inspired by Conan novels and gothic horror, Arneson expanded the setting around the eponymous town, castle, and multi-level dungeon using ideas borrowed from The Lord of the Rings and Dark Shadows and made use of the Fantasy Supplement rules from the Chainmail game.

[4] The origins of the Blackmoor setting lie in the Castle & Crusade Society, a subgroup of the International Federation of Wargaming specializing in medieval miniatures combat; the group was initially driven by Gary Gygax.

Dave Arneson was among the first to join the Society in April 1970, and many other members of his Twin Cities gaming group followed, including Duane Jenkins, Bill Hoyt, Ed Werncke, Mike Carr, and Marshall Hoegfeldt.

Within months, the leadership of the Society had decided to form a fictional "Great Kingdom", with parcels of land awarded to and contested by members of the organization.

[5]The next issue of Corner of the Table promised "the start of the 'Black Moors' battle reports, a series dealing with the perils of living in Medieval Europe".

The Barony of Blackmoor formed the centerpiece of the game, and the various players attached to it (Greg Svenson, David Megarry, Dan Nicholson, Duane Jenkins[citation needed]), initially represented the forces of good.

In the summer of 1972, Arneson famously wrote an article detailing "Facts about Black Moor" for Domesday Book #13, which brought his innovations to the attention of the rest of the Castle & Crusade Society.

[8] It added rules, monsters, treasure, and the first published role-playing game adventure, the "Temple of the Frog", a scenario from the Loch Gloomen section of the Blackmoor campaign.

Only a relatively small amount of original material, primarily link text, was written specifically for the First Fantasy Campaign, though all maps and some connected illustrations were redrawn and relettered by the Judges Guild's Bob Bledsaw.

In a subsequent re-release of the world of Greyhawk for the Advanced Dungeons & Dragons game, an arctic region of mysterious black ice in the northwestern area of the map was called Blackmoor.

When the history of Mystara was codified, it was established that Arneson's Blackmoor had existed in the world's distant past, achieved a technologically advanced civilization, and then destroyed itself in a global catastrophe that shifted the planet's axis.

For instance, The Wrath of the Immortals, an epic adventure which described a massive war involving both heaven and earth, climaxes with the discovery of the preserved control room from the starship that had crashed near Blackmoor millennia ago.