I’ve been working on a pulpy adventure campaign setting set in an underground/Hollow Earth world set in the 1960’s . It’s essentially a Kennedy-era dungeon crawl. I’ll most likely use Savage Worlds as a system, or possibly Hollow Earth Expedition.

Inspirations & Influences

Three influences – two real, one fictional

Project Mohole – A scientific project in the early 60’s to drill through the Earth’s crust to reach the mantle. They managed to drill deeper than any one had before, but didn’t reach the mantle. After a series of cost overruns, and some bad press, the project was cancelled.

American Miscellaneous Society (AMSOC) – An informal group of scientists studying various branches of Earth Science.

Battle Beneath the Earth is a 1967 British-made spy thriller about a rogue Chinese general who schemes to destroy America by constructing a network of tunnels across the Pacific, and then detonating atomic weapons beneath several major American cities. It’s basically a Yellow Peril movie updated for the Cold War. It’s not really a very good movie, but it’s full of charming elements: Tunneling lasers, brainwashing, Marines vs. mercenaries deep beneath the earth. The trailer will give you the basic idea.

Campaign Idea

In my world, Project Mohole didn’t fail. It discovered the secret tunnels of a foreign power that was attempting to invade America. The invaders had developed a new kind of laser boring machine that allowed them to cut tunnels quickly and quietly through the Earth’s crust. They were attempting to place atomic bombs beneath every military installation in North America, as a prelude to invasion. The scientists of AMSOC, along with the military decided to intervene. A joint scientific/military expedition was sent into the tunnel systems. After a desperate battle, they were able to defeat the invaders.

Discovery

During the exploration of the invader’s tunnels, the explorers also discovered vast networks of natural caverns, previously unknown to science. Many of these caverns contained their own elaborate ecosystems, with strange plants and animals that were unique to that environment, or long since extinct on the surface. During the exploration of the invader’s tunnels, the explorers also discovered vast networks of natural caverns, previously unknown to science. Many of these caverns contained their own elaborate ecosystems, with strange plants and animals that were unique to that environment, or long since extinct on the surface.

Most remarkably, evidence was found of underground civilizations still in existence. Some appeared to be human (or at least related to humanity). Others were almost entirely alien. What little contact was made indicated they had varying levels of technology, ranging from Stone Age tools to artifacts exceeding current surface technology.

Founding AMSOC

Publicly, the battle with the invaders was never acknowledged, in order to prevent a panic. It was decided that Project Mohole and AMSOC would publicly be disbanded. In reality, AMSOC would become a lavishly funded secret agency, sort of a underground counterpart to NASA, dedicated to exploring the so-called “Deep Frontier”. Publicly, the battle with the invaders was never acknowledged, in order to prevent a panic. It was decided that Project Mohole and AMSOC would publicly be disbanded. In reality, AMSOC would become a lavishly funded secret agency, sort of a underground counterpart to NASA, dedicated to exploring the so-called “Deep Frontier”.

AMSOC has been able to recreate the invader’s laser borer, and will use them to open up new tunnels to explore.

Teams of scientists and military personnel will be dispatched to explore this new world. AMSOC’s charter gives the agency the following responsibilities:

Explore and map the Underground world

Collect scientific information about underground environment & civilizations

Make contact with underground civilization

Defend the surface world from any underground threat

Running the game

The campaign can start with the discovery of the tunnels, or can take take place later on after AMSOC has become established as an agency.

Limited Supplies: AMSOC teams would be well equipped, but wouldn’t have reliable supply lines back to the surface. Eventually they will run out of ammunition and food. They’ll need to live off of native food sources, and conserve what ammunition they have. This is intended to prevent the players from just blazing away and destroying all opposition with 20th century firepower.

Limited Use of Laser Borer: AMSOC only has a few of these multi-million dollar machines. They are usually used to open up new routes of exploration. Players will have limited ability to access or use the machines. : AMSOC only has a few of these multi-million dollar machines. They are usually used to open up new routes of exploration. Players will have limited ability to access or use the machines.

Who Were the Invaders?

It literally doesn’t matter. In the movie, it was a rogue Chinese general. It can be a Bond villain, Nazi remnants, or a hostile foreign power. They just need to sort of be bad guys. The campaign starts with them defeated, but they could conceivably rise again as a recurring villain.