 An early goal of the Dota 2 team was the adaptation of DotA 's aesthetic style for the Source engine . The Radiant and Dire factions replaced the Sentinel and <unk> from the mod , respectively . The appearances of each side 's heroes were adjusted to be more <unk> , with less traits specific to either faction . Character names , abilities , items and map design from Defense of the Ancients were largely retained , with some changes due to copyright issues . In the first Q & A session regarding Dota 2 , IceFrog explained that the game would build upon the mod without making significant changes to its core . Valve contracted major contributors from the Defense of the Ancients community , including <unk> and artist Kendrick Lim , to assist with the sequel . Additional contributions from sources outside of Valve were also sought regularly for Dota 2 , as to continue Defense of the Ancients 's tradition of community @-@ sourced development . One of the composers of Warcraft III : Reign of Chaos , Jason Hayes , was hired to collaborate with Tim <unk> in the creation of the soundtrack . Valve had Half @-@ Life series writer Marc <unk> , science fiction author Ted <unk> , and Steam support employee Kris Katz write new dialog and background lore for the heroes . In addition to that , Valve also had all of the heroes ' voice acting completely redone . Notable voice actors for the English version include Nolan North , Dave <unk> , Jon St. John , Ellen <unk> , Fred Tatasciore , <unk> <unk> , <unk> Taylor , and John Patrick <unk> , among various others . 
