Jataka Tattva 17.13

लग्नदशा चरभेऽङ्गे द्रेष्काणक्रमाच्छ्रेष्ठा मध्याऽधमा द्विस्वभावे व्यत्ययेन स्थिरे नेष्टेष्टसमा ।

The dasha (planet period) of the lagna (rising sign) goes by its drekkana (one-third part of a sign). If the lagna is a moving sign, the 1st, 2nd…

वक्रगस्य पाके स्थानमानसौख्याद्यपचयः ।

In the dasha (planet period) of a retrograde planet, a person's place, honour, comfort and the like decline.

त्रिकेतरस्य पाकेऽभीष्टसिद्धिः ।

Say a planet is not in the trika (group of three houses), the 6th, 8th or 12th. In its dasha (planet period), wishes come true.