It was a good idea to target a module at beginning dungeon masters — but it also had clear implications for the legal situation. Previously, when Arneson sought a 5% royalty on the whole contents of the Basic Set, he was effectively asking for money that was going into Gygax’s pocket. Now, he would instead be asking for money earmarked for his friend Mike Carr. Carr had negotiated a 2% royalty on the $5.50 cover price of all copies of In Search of the Unknown sold, either in the Basic Set or sold separately.
If anyone hoped this would alter Arneson’s calculus, it came too late: Arneson’s lawsuit would drop in February 1979. But surprisingly, that legal case would not be the biggest D&D news of 1979. In September, the disappearance of James Dallas Egbert III, who famously was believed to have become lost in the steam tunnels beneath a Michigan university, would suddenly catapult D&D to mainstream notoriety. And with that, sales of the Basic Set rose dramatically. Right before the steam tunnel incident, the Basic Set might have sold 5,000 copies a month. By the end of 1979, it was trading over 30,000 copies per month, and only going up from there.
With the Basic Set carrying In Search of the Unknown now bringing in nearly 100,000 sales per quarter and rising, the 11 cents per copy due to Mike Carr started to amount to real money, especially in pre-1980 dollars. Those quarterly royalties would likely exceed the annual salary of a starting TSR employee, and if Basic Set sales kept growing, it could easily overtake Carr’s own salary. Carr had some difficulty getting the Blume brothers, Gygax’s business partners, to honor the agreement — though eventually, they did. It turned out a module like this would could bring significant income to its author.