"Dungeon Master" debuted on 15 December 1987 on the Atari ST, and by early 1988 was a strong seller, becoming the best-selling game for the computer of all time; Bell estimated that at one point more than half of all Atari ST owners had purchased the game. Because of FTL's sophisticated copy protection, many who otherwise pirated their software had to purchase "Dungeon Master" to play the game. The Amiga version was the first prominent game to require 1 MB of RAM, likely causing many to purchase additional memory; at least one manufacturer of Amiga memory bundled "Dungeon Master" with its memory-expansion kit. As with "Wizardry", many others offered for sale strategy guides, game trainers, and map editors, competing with FTL's own hint book.