Deathworld
Deathworld centers on Jason dinAlt, a professional gambler who uses his erratic psionic abilities to tip the odds in his favor.
Bothered that he may finally have met someone superior to him, he decides to accompany Kerk to Pyrrus, despite being warned that it is the deadliest world ever colonized by humans.
There have been numerous supernovae in the region, meaning that planets in the area are rich in valuable radioactive ores, but Pyrrus is the only even marginally habitable one, and thus the only one that can support sustained mining operations.
It has a gravity of 2 g; its 42° axial tilt creates severe weather; it has frequent earthquakes and volcanic eruptions; two large moons generate tides of up to 30 meters; and finally, there are high levels of radiation.
On top of all this, life evolves so quickly that even Kerk and his Pyrran crew have to be retrained upon their return in order to survive.
Because of this harsh environment, the settlers are engaged in a ceaseless struggle to survive, which – despite generations of acclimation and a training regime harsher than that of ancient Spartans – they are losing.
The few surviving historical records show Jason that the settlers' numbers have dwindled since the planet was first colonized, and they are now restricted to a single settlement.
Jason also learns of greatly despised "grubbers", humans living outside the city, with whom the Pyrrans grudgingly trade hardware for increasingly necessary food.
After several weeks, Jason leaves the city in search of the grubbers, who live in harmony with the harsh environment.
The grubbers hate the city Pyrrans, or "junkmen", for cutting them off from space and refusing to trade food or ore for scientific knowledge or advanced technology, particularly medicine.
Every species of native flora and fauna is psionic, and all life around the city is telepathically "shouting" the same thing: "KILL THE ENEMY!"
The resulting battle ends with hundreds dead, along with the intelligence after the entire island is destroyed in a nuclear blast.
The grubbers put Jason on a stretcher and follow the quakeman as he runs from the village, accompanied by just about every animal in the area.
In Deathworld 2, Jason is kidnapped by the religious fanatic Mikah, who is determined to bring him back to the planet Cassylia, ostensibly to be tried for his various crimes but really (Cassylia does not want Jason returned, since his huge winnings have been spent and the planet has used the incident to promote the "honesty" of its casino) to help Mikah's religious movement to overthrow the government, which they consider corrupt.
He creates innovations and machinery for the clan, in the process devising a crude device that signals his location to a spaceship piloted by his Pyrran girlfriend, Meta.
One is an agrarian society living in towns and cities; the other is composed of nomadic clans that constantly fight amongst each other, strongly reminiscent of the Mongols before they invaded China and settled down.
Jason tries to infiltrate the warrior society and use his Pyrrans to wrestle the leadership of the clans away from Temujin, but is unmasked as an off-worlder and thrown down a deep cave.
Temujin does indeed prove unstoppable, but is perceptive enough to realize, at the peak of his triumph, that he has to pay an enormous price for what he has won, as his people are becoming corrupted by the easy life of civilisation and will forget their nomadic ways.
Unfortunately, when the ship was deactivated for storage, or "mothballed", it was programmed to destroy any approaching object so it could not be stolen by Earth's enemies.
This short story was featured in Astounding: The John W. Campbell Memorial Anthology which was published after the death of the famed, influential editor.
The Return to Deathworld series is a collaboration between Harry Harrison and Russian authors Ant Skalandis and Mikhail Akhmanov and has never been published in English.
The exact share of Harrison's participation is unclear, as Skalandis has also written several sequels to late Edmond Hamilton's books, and they were published in Russian under both their names.
In Deathworld vs. Filibusters, the remains of the defeated armada (mentioned in "The Mothballed Spaceship") turn to piracy under the leadership of one Henry Morgan.
As luck would have it, instead of their original target (Kerk Pyrrus), the Roogs kidnap Jason dinAlt—the only Pyrran who would even think of trying to convince the captors that "trade is better than war".
