A ritual was a type of ceremony where a series of actions were done in a specific order to achieve a desired result.
Faction Paradox achieved many effects normally done using technology through rituals. They even time travelled by ritualistically "programming" their shrines. The most noteworthy ritual was the Act of Severance. (PROSE: The Book of the War)
In Nazi Germany, the Black Coven performed occasional ritualistic sacrifices in Heinrich Himmler's castle of Drachensberg. The rituals held no purpose other than to keep up appearances in front of Himmler, who had a strong belief in the occult. (PROSE: Timewyrm: Exodus)