Though Arneson left TSR in the early 1980s, Blackmoor remained a part of D&D lore and was referred to in many later supplements. In a subsequent re-release of the world of Greyhawk for the Advanced Dungeons & Dragons (AD&D) game, an arctic region of mysterious black ice in the northwestern area of the map was called Blackmoor. However, Blackmoor would become integral to a different setting and rules-system, those of the Basic Dungeons & Dragons game.
For various reasons, TSR published two different versions of their flagship game line. Over the course of several supplements, the Basic Dungeons & Dragons developed its own campaign setting, referred to at first simply as the Known World and later as Mystara. 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 which shifted the planet's axis.
Though its influence was now central to at least one of TSR's published worlds, the actual setting of Blackmoor as Arneson described it had yet to be presented. This was finally remedied in the mid-1980s through the DA series of expansion modules, which carried a party of adventurers into Mystara's past to visit Blackmoor. The first of these, DA1 "Adventures in Blackmoor", described in general the geography and politics of Blackmoor and the means by which the characters travel there. DA2 "Temple of the Frog" expanded the scenario that had appeared in the original Blackmoor supplement. DA3 "City of the Gods" explored the starship crashed near the Kingdom of Blackmoor, from which the setting's intentional anachronisms derived. DA4 "The Duchy of Ten" dealt with a horde of invading barbarians, but was the only work not derived from Dave Arneson's original campaign notes. A fifth installment, DA5 "City of Blackmoor", was announced but was never written or published.
Though there were no further direct explorations of Blackmoor, later Mystara products continued to make reference to it. 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 which had crashed near Blackmoor millennia ago.
After the Basic D&D game and its Mystara setting were discontinued, Zeitgeist Games, where Arneson now works, produced an updated d20 System version of Blackmoor, Dave Arneson's Blackmoor Campaign Setting, published by Goodman Games, www. goodman-games.com, in 2004. Goodman and Zeitgeist also produced a Blackmoor d20 adventure module, Dave Arneson's Blackmoor: The Redwood Scar (2004) and sourcebook, Dave Arneson's Blackmoor: The Wizards Cabal (2005). In 2006 Zeigteist Games started publishing new books on their own. The 2006 release calendar includes a softcover reprint (with added content) of Dave Arneson's Blackmoor Campaign Setting, a hardcover version of the Dungeons of Castle Blackmoor, Player's Guide to Blackmoor, and the new adventure Temple of the Frog (which will have a sneak preview event at Gen Con).