(1) Guru Chandal Yoga: In any horoscope when Guru (Jupiter) is in conjunction with (1) Saturn, (2) Gulika, (3) Rahu or (4) Ketu this yoga is said to present.
(2) Nowadays the entire Vedic astrological world forgot its actual definition and only considers the conjunction of Rahu with Guru resulting in Guru Chandal yoga and it is wrong not to consider its actual definition.
(3) If anyone studies ancient Vedic text then he will come to know that Rakshas were also said to possess supernatural powers, scientific knowledge, astrological knowledge e.g the Rakshas King Ravana was a great astrologer and he wrote Ravan Samhita a text on Astrology and another Rakshas Mya wrote Surya Siddhanta. The Rakshas were also great devotees and used to perform tapa for years to appease parmatma.
(4) But the drawbacks of Rakshas described in ancient Vedic texts were (1) Egoistic approach, (2) Selfishness, (3) Greediness, and (4) away from Vedic values of life.
(5) In ancient Vedic texts Rakshas, Dattyas, Chandalas, Danavas, Asuras, and Nishachras had similar characteristics.
(6) In Vedic astrology Gulika , Rahu & Ketu represents Rakshas or Chandala and they come under the dominance of Saturn so these planets when associated with Satvik planet Guru (Jupiter) give rise to this yoga and make a person (1) Egoists, (2) Selfish, (3) Greedy, and (4) away from Vedic values of life but this Guru Chandal yoga never stops one's (1) spiritual progress, (2) education, (3) prosperity and (4) advancement of thinking level.
(7) If this yoga is present in D24 chart then because of the effect of this at school / college level the person will be opposed or punished by teachers to may be for his betterment or teachers find some uneasiness with him. If this yoga is present in D20 cahrt then here his spiritual Guru displays the same behavior toward him.
(8) In most of the tables & software the actual degrees, minutes & seconds of Rahu & Ketu are found different so they are sometimes not found at right position in D24 and D20 charts. LAHIRI'S INDIAN EPHEMERIS OF PLANETS' POSITIONS For any year gives accurate values of Rahu & Ketu.
(9) This yoga should also be judged in D27 chart.
(10) If this Yoga is present in main chart then it will also display its effects.