Vedha means obstruction. Transits are counted from your Moon sign, and each house a planet passes has one paired house. If another planet is standing in that paired house, the transit's result is cancelled; the book's main note goes further and turns it into its opposite. The pairs come from a table in Kalaprakasika, which Jataka Parijata's translator reprints. Saturn, Rahu and Ketu take Mars's row; a few planet pairs never block each other.
☕ A paired house that can block
A transit result is read from the house a planet passes, counted from the sign the Moon held at your birth. Kalaprakasika adds a check: for each planet and each house there is a second house, and a planet standing there obstructs the result (Kalaprakasika (1917 ed.), ch. XXXVI, p. 209). Kalaprakasika itself says more: a well-placed planet so obstructed gives the opposite of its good result, and a badly placed one loses its power for evil and gives good. The book's own glossary (Kalaprakasika (1917 ed.), p. 248) and Jataka Parijata's note (Jataka Parijata (tr. Subramanya Sastri), ch. XIII, p. 833) say the obstructing planet cancels the result, and Nava does that, good or bad; the note adds that the obstructing planet, if strong, can reverse it. Never reversing it is Nava's own reading. The whole table is in the card “Transit house → the house that blocks it” below; read a row as “when this planet is in the house on the left, a planet in the house on the right blocks it”.
Take the Sun in the 11th from the Moon sign. Its blocking house is the 5th: if that house is empty, the Sun's result for the 11th comes through; if a planet stands there, it is held back. Jataka Parijata's translator works exactly this case on a chart of his own, and prints the same table in a note (Jataka Parijata (tr. Subramanya Sastri), ch. XIII, p. 834). It is one table printed twice, so the two books agree as one source, not two.
The plate has six rows, Sun to Venus. The note facing it gives the rest in a line: Rahu, Ketu and Saturn take the places of Mars (p. 209). It also names the planets that never obstruct each other, the Moon with Mercury and the Sun with Saturn. Kalaprakasika's own footnote explains why astrologers care: “predictions based on these positions of Jupiter are seldom realised … the Vedhais of planets is responsible for the disappointment” (p. 210).
What Nava follows: a planet in the blocking house cancels the transit's result, good or bad. Saturn, Rahu and Ketu use Mars's row, and the pairs that never block each other are the books' two (Moon and Mercury; Sun and Saturn), plus Rahu and Ketu by Nava's own reading: those two always stand six signs apart, so on Mars's row each would block the other every day of every year. A second planet joining the transit does not lift the block.
The blocking houses
- Sun: 1→1, 2→2, 3→9, 4→3, 5→6, 6→12, 7→7, 8→8, 9→10, 10→4, 11→5, 12→11
- Moon: 1→5, 2→1, 3→9, 4→3, 5→6, 6→12, 7→2, 8→7, 9→10, 10→4, 11→8, 12→11
- Mars: 1→1, 2→2, 3→12, 4→3, 5→4, 6→9, 7→6, 8→7, 9→8, 10→10, 11→5, 12→11
- Mercury: 1→2, 2→5, 3→4, 4→3, 5→7, 6→9, 7→6, 8→1, 9→8, 10→10, 11→12, 12→11
- Jupiter: 1→1, 2→12, 3→2, 4→5, 5→4, 6→6, 7→3, 8→7, 9→10, 10→9, 11→8, 12→11
- Venus: 1→8, 2→7, 3→1, 4→10, 5→9, 6→12, 7→2, 8→5, 9→11, 10→4, 11→3, 12→6
- Saturn: 1→1, 2→2, 3→12, 4→3, 5→4, 6→9, 7→6, 8→7, 9→8, 10→10, 11→5, 12→11
- Mix-up: vedha is counted from the transiting planet. Both houses are counted from your Moon sign at birth.
- Mix-up: any planet anywhere can block a transit. Only a planet standing in that one paired house does, and some pairs never block each other.
- Mix-up: the two books are two witnesses. Jataka Parijata's translator reprints Kalaprakasika's table, so it is one source printed twice.
Frequently asked questions
Where does Nava show vedha?
In Your Period on the You tab, on the line of the transit it affects, as “blocked by Venus (vedha)” or the planet concerned. A blocked transit adds nothing to that stretch. The monthly rasi palan pages apply the same table.
Why do Saturn, Rahu and Ketu have no row of their own?
The table prints six rows, Sun to Venus. The note on the facing page says Rahu, Ketu and Saturn take Mars's places, and Nava uses Mars's row for all three.
Does vedha apply on the whole-life view?
Yes, but only among the slow planets that view places. A fast planet's vedha lasts days, too short to show on a view sliced by the quarter.
Deep dive: how the table was read
The two cells the scan left unclear, a third book's glimpse of the same rule, and what this builds on.
🔍 Two unclear cells
On the scanned Kalaprakasika plate, the Moon and Mercury rows at house 4 print a figure that could be 3 or 8. Every row of the table names each of the twelve houses exactly once, and only one reading keeps that true: 3. Jataka Parijata's reprint then prints both cells as a clean 3, so the check and the second printing agree.
📖 The same idea in Parashara
Brihat Parashara Hora Shastra has no vedha table, but its translator uses one case to explain another rule: the Sun in the 3rd from the Moon is blocked by a planet in the 9th, Saturn excepted, and a second planet joining the Sun lifts the block (Brihat Parashara Hora Shastra (Santhanam–Kapoor ed.), ch. 31, pp. 312–314). The cell is the same as the table's.
🧭 What this builds on
Transits counted from the Moon sign are introduced on Guru Peyarchi. The other check a transit gets, its bindus, is on ashtakavarga basics.