According to American scholar and Tibetologist
Turrell Wylie, ro-langs can be described in one of three storytelling formats.
Legendary A legendary story consists of an incident that occurred many years ago, and has been told of for centuries. The characters described in the stories are often labeled without names, instead with title such as "mother", "father", "prince", etc. This makes them difficult to trace back to the original event.
Epidemic In an
epidemic story, a ro-langs rises and infects many people, often in one night. The ro-langs disease is transmitted by a ro-langs touching a person on the head. The story often ends with the ro-langs being defeated.
Comatose A
comatose story takes place at a definite location, a short time ago. The ro-langs in this story do not contaminate any people and they are quickly dispatched. Old Tibetan medical practices were not always sufficient for determining if a person is truly dead. Ro-langs in comatose stories have been described as having blue eyes instead of white. This is also a symptom of a person in a comatose state. It is believed that these people "rising from the dead" are actually just waking up from a comatose state. ==Vulnerability==