Even those who have a good knowledge of astrology know that if Mars is in the 1st, 4th, 7th, 8th, 12th position in the horoscope, that horoscope is synonymous with what we have come to know as a “Manglik” horoscope. Mars represents an energy in the natural universal cycle that is associated with war and celibacy, hence its energy projection in the areas of marriage is non-conducive for the marriage union to remain         x sustainable and for the couple to remain content and happy in the relationship.

 So the question arises – why those particular houses in the chart?

The general argument behind it is that the seventh and eighth houses are considered most important in the matters of marriage - its fructification and longevity. Hence the projection of Martian energy in those houses from anywhere in the chart is not recommended. However, when Mars occupies 1st, 4th, 7th, 8th, 12th  houses in a chart, it directly projects its energy in those two houses. Using similar logic, second and fifth houses according to the South Indian method also makes once marriage difficult.

Let us examine different houses in the chart –

Mars in the first house or the Lagna - Any planet in this position affects temperament and personality. Mars in this place makes a person impulsive, thoughtless, aggressive, and extremely picky. The direct projection of the Martian energy from the first to the seventh house creates general lack of happiness resulting in dissatisfaction in marital life.

Mars in the fourth House - The fourth house is for material pleasures, land and vehicles. Thus, if Mars occupies the fourth house, it puts a question around family well-being and could force the person to stay away from one's homeland. For these people, their own relatives can create issues in a marital relationship. Presence of such energy can also cause such men to have extra marital affairs. Since the Martian energy from here is directly projected into the seventh house of marriage, it can create compatibility issues between the couple. However, fourth house Mars is still considered better than its placement in the seventh or eighth house.

Mars in the seventh place - The seventh house is the place of marital bliss. Projection of Martian energy in this place is said to be the most troublesome. For marriages, Mars in the seventh for Men's chart  and in the eighth place in the women's chart is considered most troublesome. Energy of war and celibacy as a result of direct placement of Mars in these houses can lead to widowhood or a divorce. Martian energy here can even incite immorality. The wife of such a person could be aggressive and/or immoral while also negatively impacting the health of one’s wife. If there is an alliance of Martian and saturnian energies in the seventh house, it can lead to an immoral relationship. If there is an alliance of Mars and Ketu here, it suggests a homosexual relationship. Mars in this position is considered harsh and destructive.

 Mars in the eighth place - Mars in the eighth place is considered the most harmful in the female chart, because for a female, eighth place is considered important for marriage and general happiness. Martian energy here could also shorten one’s lifespan. Mars here can also show dissatisfaction and conflict. For men, the presence of mars can prod them to seek physical pleasure outside of one’s marriage. Mars here can also represent delay in marriage. If the marriage takes place early, it can culminate into a divorce in a short time. If a woman has such a Mars in her chart, it creates mental disorder and frustration for her husband.

 Twelfth place Mars - Since this house represents bed pleasures, Mars placed in this house leads to unhappiness in marriage as a consequence of  immoral relationships.

 Mars in second place - Mars in this place is often overlooked. However, from here, it directly projects its energy into the eighth house resulting in problems around marital happiness. If the lord of the second house exudes negative energy, then such mars can result in  divorce or marital discomfort. Additionally, Mars from this house also projects its energy in the fifth house thereby directly impacting the health of one’s children. Lastly, such placement can also lead to couples quarreling over financial matters.

 Mars in the fifth place – The fifth house is the house of kids and knowledge. This Mars in the female horoscope should be specially studied. Such a Mars in a woman's chart can lead to infertility, abortion, or a cesarean during childbirth. On the other hand, it can also show her good fortune and her husband's long life. Therefore, such mars should be more carefully studied in a female horoscope. It should be noted that while matching a male Manglik chart, a compatibility can be found with a female with a fifth house mars.

However, the above results should be taken in with a grain of salt. Mars results might look harsh, but the results should be viewed in conjunction with the houses it is in, the zodiac sign it occupies, the relationship with other planets and its own status (retrograde, non-retrograde or stationary), and its position in the D-9 chart, which is mostly used to figure out timings and quality of marriage.