To understand the history of DotA, one must begin from Starcraft. In the early days of Starcraft, there was a UMS (Use Map Settings) map called Aeon of Strife (AoS) made by a modder called Aeon64 that featured a cooperative game with four heroes facing off against endless waves of computer-controlled creeps in four lanes. The players would have endless computer-controlled creeps on their side as well, except these were weaker than the enemy creeps. The familiar game mechanic of the player who last-hit an enemy unit being rewarded with money can be found in this map. The game would end once key buildings on either side were destroyed or with the deaths of all four player-controlled heroes. A second version was made so that four players faced off against each other in a 2v2 fashion with endless creeps on both teams.