Term
Parivartana (Exchange)
Parivartana is a sign exchange: two planets each sitting in the other's sign
Parivartana is a sign exchange: two planets each sitting in the other's sign. It binds their houses together as if each lord were home, making it one of the strongest links two houses can have. Picture two planets who have swapped rooms and now sit in each other's signs — each a guest, yet each holding the other's keys. That mutual holding ties their two houses into a single working unit: whatever touches one flows to the other, and the matters they govern rise or fall together. When the exchange is between good houses — an angle and a trine, say — both are lifted, and the strongest form, between the 9th and 10th lords, fuses fortune with action into one of the great yogas of worldly success. But the bond is honest in both directions: if a dusthana is one of the partners, its difficulty is carried into the other house just as surely. An exchange is less an event than a lasting marriage of two areas of life — read the pair always together, never apart.
Exchange of rashis between two lords joins their bhavas completely — maha parivartana between good houses uplifts both, while exchanges involving dusthanas transmit their difficulty (khala and dainya classes).
— Phaladeepika parivartana yogas
Detected engine-side for all lord pairs and classed by the houses involved; the parivartana rule condition and the life reports' weighted parivartana rows consume it. The 9th–10th exchange is the premier dharma-karmadhipati form.