The twelfth house rules the subconscious mind, dreams, intuition, instinct, hypnosis, secrets, and everything hidden or that is part of the mysterious side of life, namely the behind-the-scenes or underground activity that you are not aware of or that you must keep confidential.
In this house you would find self-sacrifice, done in love and compassion, to alleviate another person’s suffering and limitations.
Both psychotherapy and psychic experiences fall under this sector too, since it rules the subconscious mind. Understanding the nature of your difficulties would also fall in this twelfth house. The concept of “self-undoing” is another twelfth house activity—seeing that one is hurting oneself may not be obvious, but through therapy can come enlightenment.
This house rules both meditation and prayer. The ninth house covers the dogma of your religion (actually of all religions) while this twelfth house rules pure belief.
This house also suggests the finishing up of a long cycle. After the twelfth house you come again to the first house and begin a new cycle, so the twelfth house is a place of rest and reflection, of planning to decide what you would like to bring into the new cycle.
The twelfth house also rules places of confinement—hospitals, nursing homes, rehab centers, or even prison or jails. (In astrology, these places are all are similar and meant to heal, restore, or rehabilitate.)
This house rules compassion for those who need help and understanding. In the twelfth house, help is usually provided on a one-to-one basis, to an individual you might know who is suffering. This house differs from the eleventh house, where help is provided by organizing groups or charities, to instead bring awareness and funding to groups who have been marginalized by society and who suffer silently.
You may be surprised to learn that this is also the house of secret enemies or those who are jealous of you and who want to work at cross-purposes to you. A secret enemy may try to make you look bad or steal credit for your good work, or it could be a hacker who attacks your computer, silently, as examples. This house would point to one or more individuals that you probably cannot see but might sense or discover when their antics become more visible, triggered by an aspect (assuming you would have a secret enemy. You probably don’t.)
A little-known fact is that all large animals come under the domain of the twelfth sector.
The twelfth sector is ruled by spiritual and self-sacrificing Neptune, the planet of unconditional love and planetary patron of the arts, and the sign Pisces.