The original DotA had roots in which StarCraft custom map?

The original DotA had roots in the StarCraft custom map Aeon of Strife.

Aeon of Strife was a user-created scenario for Blizzard’s 1998 real-time strategy game StarCraft. Rather than commanding an entire base and army, players primarily controlled a powerful hero unit while allied computer-controlled forces advanced along lanes against enemy defenses.

That basic structure strongly influenced Defense of the Ancients, the Warcraft III custom map first released by the designer known as Eul in 2003. Warcraft III’s World Editor added hero progression, abilities, items, and more elaborate map scripting, allowing the earlier idea to grow into the lane-based battle arena that became DotA.

A common mix-up is confusing Aeon of Strife with DotA Allstars. Allstars was a later and highly influential Warcraft III variant, developed after the original map and eventually becoming the dominant version simply called DotA. Valve later acquired the DotA intellectual property and released Dota 2 in 2013, but the lineage begins with a StarCraft custom map.