The Drekkana chart, D-3, is the third divisional chart, formed by dividing each sign into three parts of ten degrees, the same ten-degree segments the Western tradition calls decans. It signifies siblings, courage, and personal initiative, and is also consulted for questions of the body and longevity. The three drekkanas of each sign are assigned to the rulers of the signs of its element, a scheme distinct from the Western planetary faces. The Drekkana is one of the sixteen divisional charts (shodashavarga) of jyotisha, each magnifying a particular area of life. These are the interpretive conventions of the tradition; the divisional charts are a mathematical method for extracting focused readings from the single set of planetary positions recorded at birth.
The rule is a trine construction: the first ten-degree drekkana of a sign belongs to the sign itself, the second to the fifth sign from it, and the third to the ninth, so that all three drekkanas of any sign fall among signs sharing its own element, fire, earth, air or water, which is the basis for the "rulers of the signs of its element" description above stated concretely. Some classical sources also attach a presiding sage to each of the three positions in the trine, though the specific attributions vary somewhat between texts and are less consistently transmitted than the sign-based rule itself, which is the part of the Drekkana construction on which the tradition is genuinely unanimous.