Every planet has a natural nature, benefic or malefic. In a birth chart it also rules houses, counted from the lagna. Those houses give it a second role, its functional nature. Lords of the trines are counted good. Lords of the 3rd, 6th and 11th are counted troublesome. A planet that rules both an angle and a trine is a yogakaraka. Only Mars, Saturn and Venus can be one, and only for six lagnas.
☕ Nature, and the job a planet is given
Think of a planet as a person with a temperament and a job. The temperament is its natural nature. Jupiter is gentle. Saturn is stern. The job is the houses it rules in your chart. The same Jupiter rules different houses for different lagnas. So the books judge a planet by both.
Brihat Parashara Hora Shastra sets out the rules (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, vv. 2–7, p. 341). A lord of a trine (1st, 5th, 9th) is good. The lagna lord is specially good, because the 1st is both an angle and a trine. Lords of the 3rd, 6th and 11th give trouble. Lords of the 12th and 8th act by the company they keep; the translator's note adds the 2nd. The 8th lord is counted bad, because the 8th is the 12th from the 9th. The Sun and Moon are spared this. Ruling an angle pulls a planet toward the middle: a benefic does less good, a malefic less harm.
A planet that rules an angle and a trine together is a yogakaraka (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, v. 13, p. 345). A natural malefic that rules an angle turns good only if it also rules a trine (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, v. 14, p. 345). The Sun and Moon rule one sign each, so they never rule two houses. Mercury's two signs are 4th from each other, and so are Jupiter's. Two houses 4th from each other are either both angles or both not angles. So outside the lagna itself they never pair an angle with a trine. That leaves Mars, Venus and Saturn.
Rahu and Ketu own no sign in this scheme. The book judges them by the house they occupy or the lord they join (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, v. 16, p. 346).
At a glance
- Vrishabha (Taurus) lagna: Saturn, lord of the 9th and 10th
- Kataka (Cancer) lagna: Mars, lord of the 5th and 10th
- Simha (Leo) lagna: Mars, lord of the 4th and 9th
- Tula (Libra) lagna: Saturn, lord of the 4th and 5th
- Makara (Capricorn) lagna: Venus, lord of the 5th and 10th
- Kumbha (Aquarius) lagna: Venus, lord of the 4th and 9th
- The same six are named by Raman (B. V. Raman, How to Judge a Horoscope, vol. 1, pp. 9–10), who says no seventh is possible.
- A yogakaraka is not a natural benefic. Mars and Saturn are natural malefics, yet each is one for two lagnas.
- Saturn is not a yogakaraka for Kanya (Virgo) lagna. He rules the 5th and 6th, and the 6th is no angle (Sanjay Rath, Crux of Vedic Astrology, p. 19).
- Functional nature comes from the houses a planet rules, not from the house it sits in.
- These rules change a planet's role in one chart. They do not change its natural nature.
Frequently asked questions
Why can only Mars, Saturn and Venus be yogakarakas?
A yogakaraka must rule an angle and a trine, other than the lagna. That needs two signs. The Sun and Moon rule one each. Mercury's two signs, and Jupiter's, are 4th from each other, so they are both angles or neither. Mars, Venus and Saturn are left, for two lagnas each.
Do the books agree on every lagna?
No. Raman prints a functional nature for each lagna (B. V. Raman, How to Judge a Horoscope, vol. 1, pp. 7–9). Set beside the app's rule, the two agree on 31 of the 81 places where he names one. The lagna-by-lagna verses (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, pp. 340–356) agree with it on 30 of 75, by our count. They agree on the six yogakarakas.
Does Sanjay Rath agree?
On the ones he names, yes. He gives Mars for Kataka, and Saturn for Vrishabha and Tula (Sanjay Rath, Crux of Vedic Astrology, p. 16). He writes from a different school, the Puri and Jaimini line. His agreement is still not a separate proof, because he too follows Parashara.
Is a yogakaraka always good for the person?
This page explains a rule of classification, not a forecast. The books weigh many more things before they say anything about a life: where the planet sits, its dignity, its company, its strength.
Deep dive: the rule, and where lists differ
What the app uses. Three places the lists part. What to read first.
⚖️ The rule Nava follows
What Nava follows: one rule for every lagna, read only from the houses a planet rules. The lagna lord is benefic. A planet that rules an angle and a trine is a yogakaraka. A planet whose only house is the 6th, 8th or 12th is malefic, unless it also sits in one of those houses; then it counts as benefic (the reversal the books call a Vipareeta yoga). A planet that rules a trine and no angle is benefic, even when its other sign is the 2nd, 6th, 8th or 12th. Every other planet is neutral: one that rules an angle and no trine, or neither an angle nor a trine (for example the 3rd and the 6th). Rahu and Ketu take the nature of the lord of the sign they sit in. This is a choice. The books' lagna-by-lagna lists differ from it in many places. Your Period reads the lagna-by-lagna list of Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, pp. 340–356 instead. Where that list names no verdict, it uses the same chapter's general rules: the lords of trines are good, the lords of the 3rd, 6th and 11th are bad, and the lord of an angle loses its own nature, which Laghu Parashari reads as neutral. Rahu and Ketu take the nature of a lord they sit with, as the chapter says (with several, the strongest by Shadbala: our reading); with none, the nature of the lord of their sign (our reading). Two more readings are ours: how those general rules are scored, and a planet the list names for a raja yoga made with a partner counts as benefic.
🔀 Three places the lists part
- Lords of the 3rd and 11th. Brihat Parashara Hora Shastra and Raman count them troublesome. The app counts them neutral.
- Natural benefics that rule only angles. Raman turns them malefic, and so do many of the per-lagna verses. The app counts them neutral. The translator's note (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 34, pp. 341–343) explains the blemish.
- The Sun or Moon ruling only the 8th or 12th. The books spare the luminaries here. The app counts them malefic.
None of these is a mistake on either side. Each is a different reading of the same lordship rules.
📚 Read first
This page builds on house families: kendra, trikona and dusthana and natural benefics and malefics. Next, read kendradhipati dosha.