Few would deny any longer that communism--Marxism-Leninism and its variants--meant in practice bloody terrorism, deadly purges, lethal gulags and forced labor, fatal deportations, man-made famines, extrajudicial executions and show trials, and genocide. It is also widely known that as a result millions of innocent people have been murdered in cold blood. With this understood, the Soviet Union appears the greatest megamurderer of all, apparently killing near 61,000,000 people. Stalin himself is responsible for almost 43,000,000 of these. Most of the deaths, perhaps around 39,000,000 are due to lethal forced labor in gulag and transit thereto. Communist China up to 1987, but mainly from 1949 through the cultural revolution, which alone may have seen over 1,000,000 murdered, is the second worst megamurderer. Then there are the lesser megamurderers, such as North Korea and Tito's Yugoslavia.
Obviously the population that is available to kill will make a big difference in the total democide, and thus the annual percentage rate of democide is revealing. By far, the most deadly of all communist countries and, indeed, in this century by far, has been Cambodia under the Khmer Rouge. Pol Pot and his crew likely killed some 2,000,000 Cambodians from April 1975 through December 1978 out of a population of around 7,000,000. This is an annual rate of over 8 percent of the population murdered, or odds of an average Cambodian surviving Pol Pot's rule of slightly over just over 2 to 1.