Astrology has many layers, but you don’t need to learn them all at once. This beginner-friendly guide introduces three ideas that help bring a birth chart to life: planetary rulership, decans and the twelve houses.
Different astrological traditions use different systems. We’ll explain where the methods differ so you can explore them with confidence.
A natal chart is a symbolic map of the sky for your date, time and place of birth. Astrologers commonly read it by looking at three things together:
Aspects, which are angular relationships between planets, provide another layer of interpretation. These concepts are part of an astrological tradition and are best approached as tools for reflection, not proven predictions.
Every zodiac sign has a planetary ruler. Traditional astrology uses the seven classical visible bodies (Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn). Modern astrology also associates Uranus with Aquarius, Neptune with Pisces and Pluto with Scorpio.
Traditional rulers by sign:
Modern associations: Scorpio — Pluto, Aquarius — Uranus and Pisces — Neptune. Many astrologers use both traditional and modern rulers in their practice.
Each 30° zodiac sign can be divided into three ten-degree sections, commonly called decans or decanates. Decans give a more detailed layer to the sign of a planet or angle.
The original version of this page explored several approaches. They are worth distinguishing because their rulers aren’t always the same.
In the Chaldean method, decan rulers follow a repeating sequence of seven classical planetary rulers: Saturn → Jupiter → Mars → Sun → Venus → Mercury → Moon. The series continues through all 36 decans of the zodiac, rather than restarting for every sign. For example, Aries is associated with Mars, the Sun and Venus across its three decans.
Another tradition uses the rulers of signs that share the same element. The original page referred to this as the traditional or triplicity approach. For Aries, a Fire sign, the decan rulers are Mars (Aries), Sun (Leo) and Jupiter (Sagittarius). For Taurus, an Earth sign, they are Venus (Taurus), Mercury (Virgo) and Saturn (Capricorn).
Modern versions of element-based decans sometimes substitute modern rulerships, particularly for Scorpio, Aquarius and Pisces. That’s why two astrology resources may show different decan rulers without necessarily using the same method.
While planets describe what and signs describe how, houses help describe where a theme may be expressed. Your Rising sign marks the beginning of the first house in many chart systems, and the other houses follow around the chart.
Each house has broad associations. No one placement determines a person’s experiences by itself; astrologers interpret the full chart together.
The Ascendant, first impressions, identity, physical presence and the way we approach life. This is the beginning of the chart and an angular house.
Possessions, finances, earning and spending, security and personal values.
Everyday learning, speaking and writing, siblings, neighbours and your immediate environment.
Family life, ancestry, private life, home, emotional foundations and a sense of belonging.
Creative expression, romance, enjoyment, play, hobbies and children.
Daily routines, work habits, practical service, health-related routines and taking care of responsibilities.
Close one-to-one relationships, marriage, business partnerships, agreements and how we relate to others.
Shared finances, debts and inheritances, intimacy, vulnerability and experiences of deep change.
Higher education, philosophy, spirituality, travel, publishing and the search for broader meaning.
Public roles, professional ambitions, achievement, reputation and the Midheaven.
Friendships, groups, networks, collective causes and longer-term hopes.
Solitude, unconscious patterns, privacy, spiritual retreat and what can be difficult to see in ourselves.
The original guide also organized houses by element: Fire (1st, 5th, 9th), Earth (2nd, 6th, 10th), Air (3rd, 7th, 11th) and Water (4th, 8th, 12th). This is one useful teaching framework, but it doesn’t mean a planet or sign is automatically strong or weak in any particular house.
Houses can also be grouped as angular (1, 4, 7, 10), succedent (2, 5, 8, 11) and cadent (3, 6, 9, 12), describing different ways their themes are expressed.
Consider Venus in Virgo in the 10th house. An astrologer might begin with Venus’s themes of relationships and values, add Virgo’s attention to detail, then look at how this combination relates to public life and career through the 10th house. Aspects to Venus and the rest of the chart add context.
Want to explore your own chart? Chloe’s Dream offers a Personalised Natal Chart Report ($44 CAD) with planetary placements, houses, major aspects and an individual chart wheel. If you would like to study astrology in more depth, visit Chloe’s Dream Academy.