DIGNITIES: What are they? How do I use them? 
Dignities are a method to assess the condition of a planet in your chart isolated from other points in your chart, based on its position in the zodiac. in other words, dignities tell you how strong or weak a planet is!
The five essential dignities are: domicile, exaltation, triplicity, term (bound) and face (decan)
hellenistic astrologists would argue that all essential dignities are of equal weight, while post-classical astrologists such as William Lilly argue they descend in importance.
hellenistic astrologists would argue that all essential dignities are of equal weight, while post-classical astrologists such as William Lilly argue they descend in importance.
Beginning with domicile, a planet in domicile means it is in the sign it rules. For example, Saturn is in Domicile in Capricorn, thus, Saturn in Capricorn would be expressed constructively rather than destructively. The sign opposite domicile is detriment.
Next is exaltation, a notably more complicated dignity. The Sun was assigned exaltation in Aries because it is the 1st sign of the Zodiac, and the other Superior planets were assigned the Cardinal points. Superior planets are Mars, Jupiter and Saturn
According to Porphyry, Diurnal planets (Sun, Jupiter, Saturn) were assigned exaltation to their trines while the Nocturnal planets (Moon, Venus, Mars) were assigned to their sextiles, with Mercury being the exception and being assigned exaltation to its other ruler.
Exaltation is, simply put, a sign of visibility or awareness for the planet. While not quite home, it's comfortable and can express itself well. Think of it like a new pair of jeans: they fit, you can get them on and they look good, but they don't have the familiar stretch.
We now approach triplicites! I use the Dorothean system, which assigns 3 rulers: Diurnal, Nocturnal and Participating. These were chosen due to the nature of the signs, and are still dignified, but generally accepted as less-so than the first two.
The signs and planets are divided into Diurnal and Nocturnal. Diurnal planets are the Sun, Jupiter and Saturn, and the Diurnal elements are Fire and Air. Nocturnal planets are the Moon, Venus and Mars, with Water and Earth signs composing the Nocturnal signs.
A planet in triplicity isn't comfortable or in control like they are in Domicile or Exaltation, rather, they're doing just fine and might find $50 on the ground. I like to think of it as a position of luck. or equivalent of being in the right place at the right time.
The assignment of triplicities is a bit convoluted, so I will link a site that it explains the different systems better than I can, along with all my other sources!
Next is terms, which, according to astrologer Lee Lehman, have the most arcane and obscure origins, making it difficult to understand the logic behind them. There are three term systems: Ptolemic, Chaldean and Egyptian
Planets in term are notable, though not necessarily fortunate. There's a degree of uncertainty with planets in term regarding outcome, but importance is always guaranteed. The best metaphor I can come up with is taking: SOMETHING will happen, but what?
Last we have faces or decans, which, in terms of dignities, are not particularly dignified at all according to astrologers like Lehman and Lilly, and serve to prevent a planet from being peregrine, or malefic due to a lack of dignity.
Faces are a bit like a nagging anxiety, and a planet in face only is uncomfortable, like the jeans are definitely a size too small.
Accidental dignities are when a planet is dignified for reasons OTHER than its position in the Zodiac. This is usually houses, but not always, as it could be due to its aspect, speed, etc.
rest of thread here
