The Others Realms of Earth

You know Horrors is up on kickstarter, don't you? 

https://www.kickstarter.com/projects/1842635065/horrors-the-scary-story-rpg
With that said, lets move on to the other realms of Earth.

As humans we can only see a specific range of light and hear a specific range of sounds.  Sound too high or two low goes unnoticed. Light too red or too blue becomes invisible to us. But in this limited range we perceive the world and declare it to be all that there is.

However, this is not the case. There are many realms of existence, layered on top of each other just outside of what we can perceive. Some of these realms are closer than others, although "closer" may be a misleading term as their spacial distance is almost irrelevant. These realms layer on each other over the same physical space, interacting in ways both unseen and terrible. 

The list of known realms are, from closest to farthest: 

• The Spirit Realm- also known as the Realm of the Unseen and the Realm of Magic. In this Realm the restless dead linger, watching the living and wanting what they cannot have.
• The Dream Realm- When a person dreams their consciousness reaches deep and enters this realm of reality. Or maybe the dreams of billions of humans bled through and pooled to create this realm. Whichever the reason, the Dream Realm can seem like pure bliss, as long as you don't go any further.
• The Nightmare Realm- Not all dreams are good ones, and even the bad ones might not be the kinds of night terrors that exist in this realm. Those that know enough to recognize these realms theorize that this isn't a realm in itself, but instead merely the intersection of it's two neighbors.
• Hell- The realm of eternal pain and suffering. Although called different names, this realm is almost universally recognized by every culture. Anything that naturally exists in this realm is something of purest evil and terror.
• The Outside Realms- On the layers outsider of Hell things become less physical and more conceptual. Human minds struggle to find shape and form, and often misinterpret what they are seeing. It is hard to tell what these realms, or anything beyond them, are truly like.

There is speculation of a Realm of Glory, your Paradise or Heaven or Valhalla. Although no such realm has been experienced many take the existence of Hell as proof that Heaven must also exist. Some say it must lay beyond the Outside Realms, where it cannot easily be reached. Some speculate that perhaps the realm just cannot be accessed without invitation. Some don't say anything at all, afraid that speaking their horrifying theory aloud will only confirm it to be true...

Although invisible to most the realms are not inaccessible. Often people born at the right time, or under the right circumstances, may naturally be able to see into the closest realms. Some may develop the skill to access them, such as lucid dreaming or magical / religious ceremony. Sometimes you can access them with the right state of mind, or perhaps the correct application of chemicals to the brain. The phrase "bad trip" comes to mind. 

The realms can also naturally bleed into each other. These happen in very specific instances, like a site of massive death or a place of repeated unspeakable acts. Sometimes this happens in more unusual places, like the spot where many pass through but none ever stop (like an old subway station), or maybe points designated as a safe haven for weary travelers (like an abandoned rest stop on the side of a highway). Underused points of significance can cause the veil between realms to run thin, and two way access to occur.
So people can stumble into another realm or, more terrifying, something can stumble out. Something not summoned or controlled by any snake cults. Something lost, scared, and hungry.