Influences: old school Gygaxian D&D, Stargate, hell from the Hellraiser movies, Alice in Wonderland (and the most escellent JAGS Wonderland), The Atrocity Archives, The Cube, Aliens, The Bourne films, Species.
In 1963- post test ban- a nuclear detonation under the Nevada desert knocked a hole in reality.
The bomb was something new- and still classified- but what it did was stab through the fragile skein of normal spacetime the whole visible universe occupies, and opened a hole into something stranger.
The Fed put a door and a lock onto the hole- ninety tons of steel and titanium strong enough to bounce nukes. They kept it secret too. The place the hole opened into was just to weird for people to know about or deal with. It's variously called The Basement, Downstairs, and for those who hide behind terminology, the "Subterrestial Operational Theater".
In the late 70's, one of the young computer boffins working on the project called it "Gygaxland".
By the 90's, everyone was just calling it "The Dungeon" despite the term being officially verboten.
The name fits though. Under reality, in realms so strange they defy scientific models to explain, someone or some thing built tunnels, chambers, traps, lairs... but also filled it with wonders and treasures- including objects and devices which could quite simply, do the impossible.
Project: LONG STAIR was born.
Efforts to map the Dungeon proved difficult (and extraordinarily dangerous) for the Marine and special forces survey teams sent down. The place seemed to change, slowly but inexorably, and entirely unpredictably. Maps go stale, get rancid.
The dangers from the cruel and arbitrary traps (and the constant minefield stress they engender) is bad, but the inhabitants of the dungeon are worse. There's no other word but monsters. Alright, there IS another word- "Xenofauna"- but nobody uses that except in reports.
Most don't live long when brought Upstairs- weakening and dying in minutes, days, weeks. Some of the more impossible creatures just evaporate when they cross the threshold. Others are more insidious in their efforts to escape the Dungeon. Some of the survivors of early delves came up changed, infected.
Compromised agents were first studied (for "studied" read "vivisected"), but some proved somewhat stable psychologically, and demonstrated an intuitive understanding for the Dungeon and its ways. The NATIVE SONS program sought to use these hybrids as trackers and guides in the hostile new frontier, and teams accompanied by them showed dramatically higher success and lower mortality rates. The hybrids are stuck between upstairs and downstairs though- if they spend too much time in either world, they'll start to degenerate or sicken, go mad, or transform into something worse. They need to delve to survive.
The Americans poured money and men into the Dungeon, extracting from it miracles. Impossible devices. Unique wonders. After JFK's assassination, ever US president wears a talisman which renders him immune to gunfire. Reagan's near-assassination was the result of its removal at the behest of Jerry Falwell who declared it to be ungodly. Reagan’s tendency to let slip information about LONG STAR was a constant aggravation for the project’s controllers, but the president loved the project and pushed his allies in Congress to fund its cover programs massively through is two terms. His fear of what the Russians might do if they had access to the Dungeon drove him.
And with good reason.
LONG STAIR wasn't the only place the Dungeon impinged on normal reality- the Soviets punched a similar hole in 1984 under Degelen Mountain.
Then, through the 80’s and 90’s, following close on the heels of nuclear weapons proliferation, new portals to the Dungeon were opened in China, France, and the UK. Following on their heels, Israel (though, never officially confirmed), India, Pakistan, and most recently North Korea (though, the North Korean portal is unstable, small, and dangerous to pass through).
The secret proliferation of subterestial technology (dungeon devices, monster tech, or ‘magic items’) has flowed out through the military industrial complexes and intelligence communities of the nations controlling Dungeon access- scrying bowls guide missile strikes, rings of invisibility hide black-ops wetworkers, and in a top secret lab adjoining Los Alamos, a team is working to unlock the secrets of a gnarled staff of ancient wood which in the hands of a panicked soldier, incinerated hundreds of attacking sunterrestials.
The collapse of the Soviet state saw the huge stockpiles of dungeon artifacts broken up, looted, stolen, sold off. Now keeping a lid on the stuff is getting harder and harder, and more is leaking out all the time.
Perhaps worse, every breach into the Dungeon has been followed by an increase in so-called fortean phenomena. Nothing as overt as monsters in the street, but probable hauntings, psychic events, missing time, UFO sightings, and even some semi-credible criptozoology. The most common are the voices- weird, semi-audiuble hallucinations which almost makes sense. Those who hear them are usually labeled schizophrenic, but they don’t respond to medication. And every year, the voices get a little louder, and a little more intelligible. Those who recognize them as a dungeon-linked phenomena are extremely worried.
The world is getting stranger.
And so… that’s what I have.
Espionage, D&D style magic items dropped into an otherwise normal world, specop dungeon crawls, half-breed Pc’s, and the secret proliferation of impossible artifacts.
