The following defines each planet by ascendant, its particular effects as lords of certain houses. The Sun, as ruler of house 9, shows the basic ethical or spiritual orientation of the Sagittarius soul, its sense of law, harmony and beneficence, its inherent capacity to rule and give favor. Yet, on the negative side, it can show a too egoistical sense of principle. It is very auspicious.
The Moon, as ruler of house 8, shows their profound emotionality that gives them an interest in what transcends death. Their dedication to their principles is often to the death; if afflicted, they may kill others for them. It is generally neutral but can cause problems, like disease, as the lord of the eighth, if under malefic influences.
Mars, as ruler of houses 5 and 12, shows their strong passion and creativity which, if afflicted, can indicate loss through passion or progeny. On the positive side, it gives good perception and possible spiritual discrimination. It gives gains and is generally auspicious.
Mercury, as ruler of houses 7 and 10, shows their basic mental impulse toward power, prestige and social preeminence that can lead them into excessive action. Sagittarius types may seek partnership based upon status and such relationships may be transient or superficial. Mercury is generally inauspicious, particularly when weak in the chart.
Jupiter, as ruler of houses 1 and 4, shows their close identification of self and mind. They can be influenced by traditional or family beliefs and possess much faith and contentment in life. This can make them too conservative, however. Jupiter is auspicious as the lord of the ascendant.
Venus, as ruler of houses 6 and 11, shows a tendency towards excess enjoyment, self indulgence and extravagance. Sagittarius types may be overly confident and optimistic and lack the capacity to discern between their own wishes and the good of all. They suffer from indulging in their beneficence, just as they prosper in purifying it. Venus is rather inauspicious for them.
Saturn, as ruler of houses 2 and 3, shows an impulse towards wealth that can be manipulative. There may be a harshness of speech that can cause enmity. These types are strict about financial security, though they can be careless with what they think is extra. Saturn is probably their worst planet but Venus is nearly as bad.
The Sun and Mars can give Raja Yoga, great prestige, and are generally good for prosperity and beneficence. The Sun and Jupiter (ruling houses 4 and 9) give spiritual knowledge. Venus and Saturn (rulers of houses 3 and 6) together give vanity and a materialistic outlook on life, which can bring disease. Saturn can cause a downfall and warp their values.
As a mutable and fire sign, Sagittarius types have the most critical minds. They are dramatic and expressive but not always prudent. Their planets tend act quickly and decisively but not always consistently.