Malefics thrive in effort-houses
The single most useful rule: Saturn, Mars, and the nodes transit FAVORABLY in the 3rd, 6th, and 11th from the Moon — the upachaya and effort houses (n15). Hard planets do their best work where struggle, competition, and gain already live. This one line covers most malefic-transit reading.
Saturn transiting the 11th from the Moon is a classically productive, gains-oriented window.
Jupiter and Venus like kendras and trikonas
The benefics transit well in the houses of fortune and stability. Jupiter is favorable in the 2nd, 5th, 7th, 9th, and 11th from the Moon; Venus is favorable almost everywhere — the 1st through 5th, plus the 8th, 9th, 11th, 12th — the gentlest transiter of all. Grace planets bless the seats of grace.
Jupiter transiting the 5th or 9th from the Moon is a hallmark fortunate window.
The luminaries and Mercury
The Sun transits favorably in the 3rd, 6th, 10th, and 11th from the Moon — an authority-and-effort planet, its 10th added to the malefic set. The Moon itself favors the 1st, 3rd, 6th, 7th, 10th, 11th. Mercury, taking colour from context (n13), favors a wide businesslike spread: the 2nd, 4th, 6th, 8th, 10th, 11th.
The Sun transiting the 10th from the Moon supports visibility and action; Mercury the 10th aids negotiation.
The unfavorable set is a complement, not one list
There is no single fixed 'bad-house' list for all planets. A planet's unfavorable houses are simply the ones its favorable list leaves out — so they vary by planet. For the pure malefics (favorable 3, 6, 11), that leaves 1, 2, 4, 5, 7, 8, 9, 10, 12 unfavorable; the classically most-stressed of these are the 1st, 4th, 7th, 8th, 12th — pressure on body, home, partnership, and peace.
Saturn's 4th (home) and 8th (the Dhaiya windows) weigh; but its 5th and 10th are also outside its favorable 3-6-11.
Nature meets house-class
The whole table is nature (n13) meeting house-class (n15): hard planets suit hard-work houses (3, 6, 11), gentle planets suit fortune houses (kendras, trikonas). When you forget a table entry, derive it — ask what this planet wants and whether this house offers it, rather than reciting.
Mars in the 3rd (courage, effort) from the Moon fits; Mars in the 4th (peace, home) grates.
Same house, opposite result by nature
Because nature decides the verdict, a benefic and a malefic in the SAME house from the Moon read oppositely. A malefic in the 4th pressures home and peace; a benefic in the 4th softens and supports them. This is why 'favorable house' is always planet-specific — the house alone never decides.
Saturn in the 4th from the Moon is heavy; Venus in the 4th is comforting.
The one idea to keep
Malefics love 3-6-11; benefics love grace
The gochara table reduces to a pattern: hard planets transit well in the 3rd, 6th, 11th from the Moon, gentle ones in the kendras and trikonas — and each planet's unfavorable houses are just its own complement. Read the planet's nature against the house's class, then refine with the obstruction rules to come.