There are two major compatibility guidelines in astrology: signs of the same element are attracted to each other and understand each other easily and signs of complementary elements have great communication and are favorable for long-term relationships. Zodiac signs are divided into four elements: fire (Aries, Leo and Sagittarius), earth (Taurus, Virgo and Capricorn), air (Gemini, Libra and Aquarius) and water (Cancer, Scorpio and Pisces). Complementary element combinations are fire with air and water with earth.
There may be attraction and deep understanding between people with the same sun sign, but these couples are not always ideal in the long term. The relationship can become predictable and monotonous. For example, two Virgos can irritate each other, exaggerating each other's faults and over-analyzing each other. However, two Pisces can be very happy together, communicating on deep levels and respecting each other's need for understanding.
Most opposite signs can make great love matches with some effort. These people generally complement each other very well. Such a relationship can be comfortable and well balanced as long as those involved allow each other to be themselves. For example, a Sagittarius and a Gemini can enhance each other's natural talents and visions.
Adjoining signs often have an initial attraction and sexual compatibility. However, these signs are always of incompatible elements. This means that the relationship can be fulfilling, but it requires patience, communication and acceptance.