Rainsford comes from New York City, and he served in World War I (1914–18). He has written many books about hunting, and he has learned a great deal of hunting lore and "woodcraft" from indigenous cultures in Africa and Asia. He seems to be a morally upright man who is appalled by General Zaroff's practice of "hunting" humans, which Rainsford calls murder. Rainsford is able to keep his head and think strategically when under pressure.
General Zaroff is a Cossack who left Russia after the Russian Revolution (1917). The Cossacks are a people of Russia and Ukraine. In the 19th and 20th centuries Russia used Cossacks extensively in military actions against rioters and revolutionaries as well as the civilian population. While some nobles lost everything in the revolution, General Zaroff had invested heavily in the American stock market, and his fortune remained intact. He had always loved hunting more than soldiering, and in his exile he devoted himself to hunting big game all over the world. He got so good at hunting it started to bore him. He now hunts human beings, chiefly shipwrecked sailors he lures onto the island with deceptive channel lights. He is wealthy, cultivated, and morally bankrupt.