In Astrology, retrograde planets have always been discussed. Many conflicting definitions of the planet retrograde is found in classical texts of astrology. As a result of which it becomes more difficult to figure out the exact behavior of retrograde planets from classical texts of Astrology. 

Some astrologers believed that when a planet gets into retrogression a transformation can be seen in each individual planet. For example, the qualities of Jupiter get transformed into Venus, the qualities of Mercury gets transformed into Mars, the qualities of Mars gets transformed into Mercury and that of Venus to Sun. Saturn changes into the qualities of Mars. These pairs of planets are obstructive to each other. If anyone of them become retrograde they do not behave like enemies. Their inimical nature is restored if both of them are retrograde. For example let us considered that Venus is retrograde and it is in conjunction with sun then both of them become friends and do not behaves like enemies. The case is also similar for Mars and mercury conjunction. If anyone of them becomes retrograde then they behave like friends. But at the same time if Mars and Mercury both become retrograde then they behave like enemies. This research is published by Dr. M.Subba Rao in his essay in a seminar on the Indian Institute of Devine Science on 29th July 2012 at Kowtha Kalyan Mandapam.

The placement of retrograde Saturn alone without any conjunction or aspect becomes very strong in upachaya houses (3rd, 6th, and 10th House). For example, if retrograde Saturn is posited in Aries or the Scorpio sign then there is no problem for Saturn as the qualities of this retrograde Saturn are similar to the qualities of Mars. Similarly the retrograde Saturn does not face any problem in the houses of Jupiter, Sun, and Moon because they are friends of Mars. 

If Rahu or Ketu or Mercury is in conjunction with retrograde Saturn then the results will not be pleasurable but if the Mercury is also in retrogression then it becomes auspicious. This explanation is given based on the fact that the Veddhaka of Mercury is Mars. 

However it is also necessary to analyze the D-9 and D-60 charts of the native before reaching any conclusion.

Few points to remember

1. Retrograde planets are in an introspective mode.
2. These planets try to learn from planets aspecting or in conjunction with them.
3. These planets show an inclination of qualities towards their Vedaka planets.
4. If any exalted planet is in conjunction with the retrograde planet then the retrograde planet also become strong.

Some astrologers considered that outer planets like Uranus, Neptune, and Pluto are not having any influence on human life because their periods are too long and rarely consider their motion while predicting future events. But these outer planets also have an impact on human life which will become clear in my Upcoming articles. The planets Mercury, Venus, Mars, Saturn, and Jupiter becomes retrograde for a certain period every year. Since mercury is the fastest orbiting planet around Sun it is observed that in a year there are three times when Mercury becomes retrograde. 

Please note that the influence of Sun, Moon, Ascendant, and the free will of the native must not be neglected as they have significant amounts of influence on the native. The free will of a person becomes more important when there's a retrograde planet in the birth chart. James Braha made it very clear that if the ruler of a particular house is retrograde then significations related to that house cannot be activated or it does not completely depend on the person's desires.

Retrograde planets show a deep influence from the past life and as a result it may become a constant point of focus for the entire lifetime. 
Unfulfilled desires are connected to the planets in retrogression. However if these retrograde planets are connected to strong planets then it gives the native necessary energies to work positively and reach greater heights of life. If three or more planets are in retrogression then things are achieved unusually and are not understood properly. 

The placement of retrograde planets with respect to the ascendant.

1. If the lord of the ascendant becomes retrograde then the native's outgoing tendencies get highly diminished. The native faces hard time in gaining recognition. Such a retrograde planet becomes pernicious to the progress in career.

2. If the lord of the second house becomes retrograde then the native receives money at very slow rates. If such a person possesses writing skills then he is probably not going to use it till later age.

3. If the lord of the third house becomes retrograde then a person's higher ambitions become less. He will not desire much and the chances of having younger siblings get highly diminished. The person may not be following his hobbies but at a later age, he may start following his hobbies which could be music,  dance or art.

4.  If The Lord of the fourth house becomes retrograde then there is very little chance that the native owns a land. He may have very little desire to get higher education. However it must not be concluded that the person cannot acquire higher degrees and as it simply means that the planet is afflicted and will manifest very slowly.

5. When the lord of the 5th house becomes retrograde the person will not have much desired to have kids. The person may not be desirous of sports, politics, spirituality and the matters related to the 6th house are not felt till later age. 

6. If the 6th lord is retrograde then the recovery from any illness or operation becomes a serious issue. 

7. If 7th lord becomes retrograde then the person may not think of going into business till the later age and the marriage or matters associated with spouse becomes afflicted. The marriage is either not enjoyable or the trustworthiness with the partner is missing.

8. If the 8th house  Lord is retrograde then the chances of getting money through inheritance come after a lot of struggle or it may come after a great amount of effort by the native which is often very stressful and delaying. At later ages of life the person may become more interested in Astrology or matters related to the occult science such as tantra.

9. James Braha says that if the Lord of 9th house is retrograde then it may lessen the desire of the person for religious or spiritual activities. It also lessens the desire of the native to travel long distances.

10. According to James Braha when 10th Lord becomes retrograde, it the least desirable since it weakens the ability of a person to perform well in his profession.

11. The possibility to have an older sibling is very less if 11th Lord gets into retrograde motion. He may not have the desire to make new friends and may face problems with friends. The house 11th, 5th and 7th are considered the house of desires and it may take a long time and effort to succeed in these areas.

12. If the lord of 12th becomes retrograde then his sexual desire is very less and he does not desire to go to a foreign land and it may also indicate lack of peace of mind. Retrograde planets do not harm the native unless it is in conjunction or in aspect with the malefic planet.

Whenever retrograde Jupiter or Venus becomes the lord of the 10th House they give a complete impact on career. A benefic planet being retrograde can definitely strengthen the house where it is situated. However malefic planet being retrograde can cause a certain amount of harm to the natives if they are not being aspected or in conjunction with beneficial or friendly planets.

Whenever retrograde Mercury becomes the lord of the 10th House the person may have an inspiration to select a Mercurial career such as writing, teaching, or becoming a lecturer, etc. The person's desire plays a huge role in those areas that are ruled by retrograde planets. The houses that are ruled by retrograde planets are held back in the earlier age of the native.

Malefic planets like Mars in retrogression, if placed in the 4th house of the native can cause a great amount of pain to the mother. However the results are not the same whenever the same planet is moving forward.

If retrograde Saturn becomes the lord of the 7th house then the person has some amount of karmic debts of love and it is only after the karmic debt is overcomed by the person, can make a good marriage assuming no other afflictions are there for Venus or the 7th house.

Whenever Jupiter becomes retrograde it shows a decline in the knowledge and patience of the native. Normally in the period of retrograde Jupiter peoples re-evaluate their ethics. If a person has retrograde Jupiter, it is indicative that he was probably a drunkard in his past life. If Jupiter is retrograde in a chart then the person constantly tries to seek truth and deeper meaning of life but rarely achieve that level of understanding. The person actually strives to find the right spiritual balance within themselves. The person feels a lack of spiritual fulfillment or may feel as if he is tugged by the regulations of his path of spirituality or philosophy.