"The Isle of Dread" was the first published adventure for any version of "Dungeons & Dragons" to focus on wilderness exploration as a major theme. This would go on to be an important element in many other adventures, including most of the rest of the X-series. It also introduced numerous creatures to the game for the first time, including the kopru and "aranea", both of which went on to find a place in the Third Edition "Monster Manual"; the "rakasta" and "phanaton", both of which would later appear as playable races in other "Dungeons & Dragons" products set in Mystara; and many others, including several types of dinosaurs.