?? What world are you from???
Not sure the context from which you are asking this question.
Mao was a evil man, who was responsible for the deaths of tens of millions. However, his single most deadly act, imposing the Great Leap Forward, was a bureaucratic act. Mao decreed collectivization of agriculture and would not budge from that path. Local officials would not dare challenge his faulty assumptions, and a famine that killed 30-55 million people resulted.
Compared to that bureaucratic atrocity, the Chinese Civil War killed 2-3 million, his inaction against the Japanese invasion of China (to weaken his rivals), was indirectly responsible for an unknown portion of the 15-20 Chinese war dead, and the Cultural Revolution killed between 1-20 million.
Even with the worst numbers, Mao still kills more people through incompetence, than though direct, indirect, and influenced acts of violence. Making him unique among monstrous world leaders.