Open door technology was invented and used by the Great Houses during the War to combat Faction Paradox's Remote experiments on Native American tribes during the 19th century. Timed to coincide with primitive occult portents such as solar eclipses, these were the eyes through which the Great Houses delivered pre-recorded messages of salvation and freedom from European encroachment, complete with iconography specific to the recipients' regional culture. The consistent theme was that heaven on Earth and the resurrection of dead loved ones would be possible if local tribes rejected European technological wonders. In this way, the visions were designed to counter Remote-style techno-fetishisation.
The project had many early successes like Tenskwatawa, but Faction agents quickly learned how to hijack the open door transmissions. For instance, Wokova saw not a miraculous vision but a trailer for Michael Brookhaven's 1990 film The Coyote Road. Other Faction messages included rituals that would raise multitudes of the dead to form heavily-armed ghost armies (like those led by Pai'ngya in 1877).