Bhadra is one of the five Pancha Mahapurusha yogas, the great-person combinations of jyotisha, and it is the yoga of Mercury. It forms when Mercury occupies its own sign, Gemini or Virgo, or its sign of exaltation, Virgo, while standing in a kendra, an angular house from the ascendant. The tradition reads Bhadra as conferring the Mercurial virtues in strength: sharp intelligence, eloquence, skill in learning and commerce, wit, and a youthful, versatile vigour, giving a person of the learned and articulate type. These are the interpretive conventions of the tradition; the yoga is a defined placement of Mercury in dignity and angularity, one of the five that together are held to mark out an exceptional nativity when the planet involved is strong and unafflicted.
Bhadra is structurally unusual among the five: Mercury's own signs are Gemini and Virgo, and its sign of exaltation is also Virgo, so a single sign, Virgo, satisfies both possible conditions for the yoga at once, a doubling no other Mahapurusha yoga shares, since the other four planets are exalted in a sign different from either of their own two. Classical commentators note this coincidence as giving Mercury in Virgo, angular from the ascendant, an especially strong claim to the yoga compared with Mercury simply owning Gemini. As with Ruchaka, Mantreswara's Phaladeepika extends the reckoning to the Moon as well as the ascendant, a position Brihat Parashara Hora Shastra itself does not take, so authorities differ on whether a Mercury angular from the Moon alone, but not from the ascendant, qualifies as Bhadra at all.