Horary was established as a fourth branch of the astrological tradition in the early medieval era, along with ‘mundane’, ‘natal’ and ‘electional’. In horary, you cast a chart when you ask a question, seeking an answer to and resolution of the question in that moment’s planetary configurations.
Horary is divinatory of nature and requires discipline and integrity from those who ask a question (client) and equally those who give an answer (astrologer).
Against or beyond
Asking a horary question comes after your honest concern over the matter and conscious choice to seek further assistance. The planets respond in symbology; you interpret their symbolic language. It can go against or well beyond your expectations, since the only thing the planets ‘care’ about is the truth (and truth hurts sometimes).
Let’s assume that the question is about your relationship. Normally who asks the question (or the querent) is represented by the 1st house/place ruler planet. The (significant) ‘other’ is represented by the 7th house ruler planet. So if the 1st house falls in the sign of Taurus, the ruler is Venus, the 7th is then in the sign of Scorpio, hence the ruler is Mars. You then examine: where are these planets in the chart, and what aspects are there in between them, if any? Are the aspects harmonious or difficult? Are they in angular placement (thus strong) or cadent (thus weak)? Are they with or without dignities?
I said ‘normally’ because often the querent asks on behalf of someone else. For example, a mother asking about her daughter’s relationship: is she in the right relationship with her partner? Then, the mother/querent (1st) is asking about her daughter (5th house of children) with regards to her daughter’s partner (7th house of relationship from 5th/daughter = 11th).
The planets and the luminaries are constantly moving. Which means that answers revealed in a horary chart are not static either. They develop over time.
Not only can you see a resolution of the question in the chart, you can also see ‘when’ that is likely to happen. Positions or degrees that the planets occupy in the chart are indications as to ‘when’ in the future that happens as well as if/when something vital to the question has already happened.
The moon, as the most moving entity, assumes a vital role in ‘timing’ the situation under question. For example, a missing thing as ‘movable object’ is signified by ruler of the 2nd house of possession/belongings, but the Moon also shows important clues to whereabouts or state that the object is in. Again symbolism is most indicative: what phase of light the Moon is in, from which sign to which sign it is moving, involving what planets, etc..