Parivartana Yoga (exchange yoga) occurs when two planets are each placed in the other's sign of rulership. This creates a mutual reception — both planets act as if they are in their own sign, and there is a strong functional connection between the two houses involved. The yoga is classified by the houses exchanged: Maha Yoga (great) when both houses are kendras or trikonas; Khala Yoga (wicked) when one house is dusthana; Dainya Yoga (miserable) when one is a dusthana and the other a dusthana lord. Despite the names, Dainya parivartana can still manifest some positive results — the exchange always connects two houses tightly.