Normally, more physically "real" worlds seldom mix with the "less real" ones. From a place like Earth or Coracan, the dream worlds can usually be accessed only via astral projection or through sufficiently advanced technology such as dream circles. Many rules have their exceptions, though, and this is one of them.
A "dreambleed" is an area where a physical world like Earth interacts with the dream worlds. Here, the laws of physics become less constrained and all manner of seemingly impossible phenomena can exist. Gravity can break down, spirits can pass into our world, non-Euclidean geometry can exist, and in a more intense dreambleed, beings from our world can even cross into the dream worlds. Dreambleeds can take the form of a house where items seem to shuffle around when no one's looking or where shapes scurry in the corner of one's eye, or a dark forest the locals know to avoid where the path seems to wind around itself in impossible patterns, or a ball of shimmering light through which flickers of other worlds can occasionally be seen. They can form anywhere and come in countless shapes. Some only exist for a few days, others persist for centuries or millennia. Even when a dreambleed has vanished, it can recur in the same place like the aftershock of an earthquake. Ancient dreamwalkers perfected ways of preserving dreambleeds, and today, structures like stone circles or temples mark the spots where they linger.
Spirits and id often inhabit dreambleeds.
The easiest way to detect a dreambleed on Coracan is by studying the plants in the area. In a dreambleed, every green plant will die or be severely stunted, leaving otherwise-rare purple plants (which are much more resilient to dreambleeds) to dominate. An observant researcher can see these purple patches from satellite images. For humans, the sense of smell will be heightened close to and in the dreambleed due to the strong connection between smell and memory in humans. Ischerite may emit a creepy sound not unlike a radiation-measuring device if connected to an audio output.
Effect on technology
Any computerised device is likely to become filled with corrupted information, make strange sounds and behave abnormally unless protected by a cage or ischerite. Geolocation signals and telephone calls are unlikely to help. Attempting to call someone using a telephone can result in hearing anything from white noise to an unknown person calling them to hearing an entire conversation between other people. Or it might be gibberish learning to speak. Entire phone calls often get trapped in dreambleeds, causing the caller to hear conversations or calls attempted previously in the dreambleed. Even more creepily, the voices or messages may become sentient or become hijacked by an id as a trap, meaning that received messages aren't always true recordings of prior events. Sometimes there are lost beings in these dreambleeds, people for whom a fragment refuses to dissipate; sometimes they just lost their way, but sometimes they are pieces of long ended wars fought among dreamwalkers. Sometimes, the dreambleed is so fresh or strong that people can hear these voices without the aid of electronics.
Many dreambleeds are scars caused by horrific events. Many date from the Panthalassa War, but a few are older and some are many millennia old.
Effect on culture
A long time ago, dreambleeds used to be thought of as gateways and not always death traps. They were the easiest places for spirits to enter Coracan and the easiest places for people to enter the dreamworlds. They used to be guarded against id, a matter as important as protecting one's settlement from wild animals and human attack. But people forgot. They remembered the warnings, as fairy tales, nursery rhymes and sayings, but not the reason behind them.
In modern times, dreambleeds are seen as uniformly creepy places, a not entirely undeserved reputation. As a result of this, land values in and around dreambleeds are lower than surrounding areas despite limited understanding of the phenomena among the general population. In real estate and surveying, dreambleeds are euphemistically referred to as 'purple patches'. Dreambleeds are a consistently popular trope in the horror genre on Coracan.