Deathworld

Deathworld is the name of a series of science fiction novels by Harry Harrison including the books Deathworld (first published 1960, serialized in Astounding Science Fiction), Deathworld 2 (1964, initially titled The Ethical Engineer and serialized in Analog) and Deathworld 3 (1968, serialized in Analog as The Horse Barbarians), plus the short story "The Mothballed Spaceship" (1973, written as part of a tribute to John W. Campbell). The central hero is a gambler who becomes involved with colonists of an extremely hostile planet.