War Against the Cthorr–Post-Apocalyptic Alien Invasion RPG Inspiration

This is part two of my series on post-apocalyptic inspiration for a role-playing campaigns.

David Gerrold wrote the original “Star Trek” episode “The Trouble with Tribbles” and “The Martian Child” which won the Hugo award a few years back, but he also wrote the excellent “Cthorr” series. The “Cthorr” series is a brutal, grinding tale of earth after apocalyptic plagues and an alien invasion.

Now an alien invasion is hardly original, but the method of invasion struck me as novel; ecological warfare.

The “Cthorr” series does not have any bipedal gray aliens with death rays blasting the White House or flying saucers. In fact, there is no clear intelligence behind the invasion at all. The invasion is subtle and starts literally at ground level. New plants and small animals appear in the wilds, reported only by ecologists and hikers. Over time these species begin to supplant the native flora and fauna. With these new species came a series of plagues that killed billions and gave the new ecosystem time to develop. Over the space of a few years, larger and more aggressive species appeared that waged direct warfare on humanity. The title of the series “Cthorr” is the odd noise made by giant fuzzy pink worms that eat people at an alarming rate. The ecology is extremely well-defined with its own internal logic. A great deal of thought went in to the ecological design for the books and it shows.

The story develops through the eyes of Jim McCarthy, scientist and soldier on the front lines. Like most people in the series, Jim has some mental issues from all of the horrors. It is made very clear by his interactions with both “normal” people and various fringe groups that even if the war ended tomorrow, everyone is tremendously damaged mentally by the experience. .

This damage extends to the society as a whole, with some countries becoming little more than dictatorships and the military restructuring society to fight the war. It is details regarding government and society as a whole that really impressed me.

Gerrold also has a fun take on telepathy that is both amusing and slightly menacing in the series. A small part of the story, but I think it will have growing importance later in the series. There are two more book in the series that should come out soon, but they do not have a release date yet.

Yes, there is a GURPS supplement for the “Cthorr” series written by C.J. Carella. I have a copy and while adequate, it is lacking in some areas. It does not really get the “we are really, really screwed” feeling of the books across very well and leans a bit too much toward the “pulp” genre for my liking. It is also long out of print and relatively difficult to find. Even with its defects it does have a nice bestiary for a campaign. Worth picking up as reference, but still read the original books for the whole experience.

Fair warning, this series is brutal and contains some fairly graphic sex and violence. Still, it is one of the best descriptions yet of a near-future world fending off an alien invasion I have ever read.

There are currently four books in the series, listed below, with two more on the way. I suggest you check them out if you run any “Gamma World” or “Mutant Future” games, they are a great resource.

A Matter For Men (The War Against the Chtorr, Book 1)

A Day for Damnation (War Against the Chtorr, Book 2)

A Rage for Revenge (War Against the Chtorr, Book 3)

SEASON FOR SLAUGHTER (The War Against the Chtorr, Book 4)

Trask, The Last Tyromancer



Trask is a long-time gamer, world traveler and history buff. He hopes that his scribblings will both inform and advance gaming as a hobby.