An event when persons from two dimensions or universes are exchanged rather than a simple one way crossing. This sort of event is far too common between VC-Prime and Greyhawke. Checking records indicates there are possibly hundreds of such inversions since the beginning of records on Earth.
Three Inversions are known since modern times. All in recent years. Two are considered a single inversion in two events.
- Dr. Detier Klaus is exchanged with Diter the Leoman
- Sonja Traveler and Panther Walks With Him are exchanged for Leaur and Seelein
- US servicemen and Sonja Moody are exchanged for Wiliis Blackmane, Orane Blackmane, Zarra, Tendee, Candilee, and Eldirman.
All of these events listed have ended in the recovery of all persons exchanged without harm. This has not been the universal or typical case in the past. The Lost Persons Treaty was negotiated for exactly this reason. Keep in mind that inversions are not guaranteed to be to/from Greyhawke. Do not assume.
Unlike an inversion this phenomenon is one way. Something from elsewhere comes here without an exchange of mass/persons. It can be in a controlled fashion or uncontrolled. Likewise it is possible to be intruded into another universe/dimension. Those known intrusions are:
- Therilan and the Ane History Scouts are considered a dimensional intrusion. They are alien Outsiders here to study Earth.
- Favel is an alien outsider dumped in this universe due to a deliberate accident with an FTL drive.
- Recently encountered the being Raphael is from another world, or demi-plane as he calls it. A refugee from a world being swallowed by Things Man was not Meant to Know. He moved on to Greyhawke with his family of refugees. That world is closer to what he is used to in most aspects. Raphael has returned to Earth a few times.
- Tanuki rain: Tanuki are appearing on Earth. All report some matter of life threatening circumstance. No missing persons are known in association with any Tanuki.
- Humanoid cat skull found by Dr. Benjamin Carver in the vicinity of Hope, Kansas about 1876. He retained the unusual skull found dry and devoid of any flesh. The date at which it came to rest in the gully is impossible to determine. Caron 14 dating indicates a death around 1500 CE, corrected for anomalies.
- Battle of the Superstition Mt. Whether intrusion or inversion is unknown. A battle of Orcs and Humans from Greyhawke was mixed with a battle between Apache warriors and US Calvary. The date was March 1882.
- Diter the Healer lost a spell book later found by Diter Klaus. Time and place unknown.
- Elven woman that ended up in an asylum. Her effects were recovered. Again the why and how are unknown. Her remains were not recovered.
- The Phoenix Inversion. The location of the Lost Dutchman mine. Spanish conquistadors are believe to have been exchanged for the five Phoenixes, the three juveniles did not survive.. Once again in the Superstition Mountains. Date unknown.
If you find yourself in an inversion/intrusion event:
- First do not panic. Assess your circumstances and do not react hostilely to natives as a first response.
- Remember, you have no standing in law enforcement there. Be passive unless attacked.
- Seek and cooperate with officials of the Eyrian Empire, if you can find them. It is in their interest to see you get home. Pray you find these people. Not much can be done if you don't.
If you find persons that have been inverted/intruded:
- Deescalate encounters as quickly as possible. Remember they have no idea what is going on. Once violence starts it isn't likely to stop.
- Seek to communicate with such persons. Let them know that you will seek to get them home, and that measures are in place to aid them.
- Contact the State Department and the INS They will assume the responsibility for inverted persons as quickly as they can.