Who created the original Defense of the Ancients mod in 2003? Eul created it. Using the pseudonym Eul, Kyle Sommer built the first Defense of the Ancients custom map for Warcraft III in 2003.
The map drew important inspiration from Aeon of Strife, a StarCraft custom scenario, but adapted that lane-based concept to Warcraft III’s heroes, abilities, items, and World Editor. Players controlled individual heroes and worked in teams to destroy the opposing Ancient.
Eul’s version was made for Warcraft III: Reign of Chaos. After The Frozen Throne arrived later in 2003, other mapmakers continued the concept in new versions. Guinsoo became associated with DotA Allstars, while IceFrog later led its development; neither created the original Defense of the Ancients map.
That lineage matters because the original community map eventually inspired Dota 2 and helped establish the modern multiplayer online battle arena genre.