If the planets are what drives you and the signs are how those drives express themselves, the houses are where in your life each drive plays out. The twelve houses divide the chart into twelve departments of experience, from identity and self-image (the first house) to the unconscious and what lies beyond the self (the twelfth). Every planet in your chart occupies a house, and that house determines the area of life where you will feel that planet's energy most directly.
How Houses Work
The house system is anchored to your birth time and location. The Ascendant, the degree of the zodiac rising over the eastern horizon when you were born, marks the cusp of the first house. The Midheaven, the highest point of the ecliptic overhead at that moment, marks the cusp of the tenth house. The remaining houses are distributed between these two anchors according to the rules of whichever house system you use. (See the House Systems lesson in Foundations for a discussion of the different systems and their trade-offs.)
Because the houses are tied to the Earth's rotation, the entire house structure shifts roughly one degree every four minutes. This is why birth time matters so much in astrology. A difference of even twenty minutes can shift the Ascendant into a different sign and rearrange which houses the planets occupy.
The Angular, Succedent, and Cadent Houses
The twelve houses fall into three groups of four based on their relationship to the chart's angles.
Angular houses* (1st, 4th, 7th, 10th) sit at the four most prominent points of the chart: the Ascendant, the IC (bottom of the chart), the Descendant, and the Midheaven. Planets in angular houses operate with visible force. They shape the areas of life that define you most obviously to yourself and to others. These are the houses of action and manifestation.
Succedent houses (2nd, 5th, 8th, 11th) follow the angular houses and deal with what you accumulate, create, share, and receive. They are houses of resources and stabilization, concerned with what sustains you after the angular houses have established the basic framework.
Cadent houses (3rd, 6th, 9th, 12th) precede the angular houses and deal with learning, processing, and preparation. They are houses of thought, adaptation, and transition. Planets here work more subtly, often through internal processes, mental activity, or behind-the-scenes effort.
The Six Axes
The houses also operate in pairs of opposites, and understanding these axes is as important as understanding the individual houses.
The 1st/7th axis is the axis of self and other. The first house is who you are; the seventh is who you meet when you step outside yourself.
The 2nd/8th axis is the axis of resources. The second house is what you own and earn; the eighth is what you share, inherit, or lose to forces beyond your control.
The 3rd/9th axis is the axis of knowledge. The third house is everyday learning and communication; the ninth is higher understanding, belief systems, and the search for meaning.
The 4th/10th axis is the axis of foundation and achievement. The fourth house is where you come from; the tenth is what you build in the world.
The 5th/11th axis is the axis of creativity and community. The fifth house is personal expression and what you create; the eleventh is the group, the collective, and what you contribute to something larger.
The 6th/12th axis is the axis of service and surrender. The sixth house is the work of maintaining the body and the daily life; the twelfth is what lies beyond the structures the sixth house maintains.
Empty Houses
Most charts have several houses with no planets in them. Those areas of life are still active. An empty house is still ruled by the sign on its cusp, and the planet that rules that sign carries the house's themes wherever it sits in the chart. An empty seventh house with Scorpio on the cusp means that Pluto (or Mars, in the traditional system) carries the seventh house's relationship themes into whatever house Pluto occupies. The house is not empty. Its story is being told somewhere else in the chart.