Dreamgum

Created by the Ethicals of the Riverworld, Dreamgum is a form of highly addictive chewing gum. It is distributed along with their food to all Riverworlders at each evening meal in their Grails.

It causes vivid hallucinations and a certain degree of lowered inhibitions amongst users. Since the first time it was distributed no one knew what its effects were, the first night on Riverworld was an orgy of sex and violence.

After that, it became a much less popular drug, although a certain number of Riverworlders became hardcore addicts – an addiction that could not be broken by the death and resurrection, as it has no physical component.

Riverworld

Few afterlives are quite as far out as Riverworld. Riverwold is a planet that consists of a single long river valley, winding over the entire surface of the planet from the north pole to the south. It is, of course, artificially constructed. On Riverworld, every single adult human being who ever lived between the years 10,000 BC and 1980 AD has been resurrected by mysterious aliens for an unknown purpose. They are provided with food, good health (up to and including the connection of genetic defects), endless re-resurrections should they die again on the Riverworld – and nothing else.

No clues as to the purpose or rationale of the Riverworld. No nothing.

Naturally, to a certain type of personality – explorers, adventurers, philosophers and certain others – this does not sit well, and the quest to discover the secrets of the Riverworld is on.

Riverworld is, ultimately, one of those afterlives that are much more fun to read about than to visit. I mean, think about it. It’s a world in which every single human being for a span of nearly 12 thousand years has been resurrected. That’s a planet full of old grudges and the like. Not to mention that the world has largely reverted to a stone age level of technology. Check it out, certainly, but unless you’re one of those who have access to its secrets, don’t expect to enjoy Riverworld any more than you enjoyed Earth.

You don’t really think I’m going to spoil it for you, do you?
Go read it yourself!