TWELFTH HOUSE in the Horoscope

The 12th House governs your personal sacrifices and shortcomings. It's drastically called the Hell of the Zodiac (although it's a House and not a Zodiac sign). That's usually an exagerration, but it does show what parts of life you're unable to express to your satisfaction, your constant ailments and weaknesses.
The best way to describe the House is that it contains what talents and capacities of yours you are unable to express, because of other things in life (other parts of the horoscope). Here is what you sacrifice in order for other ingredients in your life to bloom.

Zodiac sign and Planet

If the House changes Zodiac sign somewhere in its span, that means your sacrifices and weakness will change - either due to the simultanwous changes of signs in the other Houses, or their change alter your weaknesses. If the House is mainly in one and the same Zodiac sign, you probably keep the same ailments and shortcomings chronically. You need to learn to live with them.
Planets in the 12th House show events regarding your sacrifices and weaknesses, but mainly what powers of yours are held back for the sake of other powers and capacities of yours in the horoscope. The planets are driving forces, so one of them in the 12th House will be inhibited - except for Neptune, which is stimulated in it because of its nature. A lack of planets in the House shows that you don't need to restrain any of your capacitites. But that may also mean you have insufficient room for recuperation and reconsidering your path. A life without significant sacrifices might become drab, because of loss of perspective.
Here are simple keywords describing the nature of your sacrifices and weaknesses, depending on what Zodiac sign you have in the 12th House. Since the House shows what is not expressed, be aware that these words describe the result of the weakness rather than the capacity suppressed:

Aries yielding
Taurus instability
Gemini boredom
Cancer carelessness
Leo anonymity
Virgo sloppiness
Libra injustice
Scorpio predictability
Sagittarius confinement
Capricorn passivity
Aquarius superficiality
Pisces pragmatism

Here are keywords for how your sacrifices and weaknesses are expressed if you have a planet in your 12th House:

Sun unrest
Moon indifference
Mercury thoughtlessness
Venus displeasure
Mars cowardice
Jupiter unlucky
Saturn irresponsible
Uranus disinterested
Neptune dreaming
Pluto accidents

The keywords are just simple clues to understand the 12th House. You need to consider the whole before deciding on the meaning of one single ingredient.

Aspects

The 12th House has the following aspect relations to other Houses:

Opposition 180° 6th House
Trine 120° 4th House, 8th House
Square 90° 3rd House, 9th House
Sextile 60°2nd House, 10th House

     These relations between the Houses are quite important when analyzing their influence. The opposition aspect to the 6th House, that of your work, is because your daily work usually consists of personal sacrifice - hwo much would you work if you didn't need the money? Also, your weaknesses are often limiting to how you can work.
     The trine to the 4th House, home and family, shows that they benefit from your ability to sacrifice yourself for them, but also home is where your weaknesses are supported and accepted. The trine to the 8th House, things beyond your control, implies that most of your weaknesses are not caused by you. Many of them are inherited through your blood-line, which is also governed by the 8th House.
     The square to the 3rd House, friends, shows that many of your weaknesses are particularly exposed and troublesome for your life with your friends, who are not always as tolerant towards them as your family. On the other hand, with some well-chosen friends, you're not reminded of your weaknesses. There is also a link in the way that you tend to sacrifice yourself for your friends, whether they demand it or not. The square to the 9th House, that of travel and new perspectives, simply states that such things are usually hindered by your weakness and incapacities. Some such changes might even cause them. Still, square aspects are soluble, if you find a proper way of dealing with them.
     The sextile to the 2nd House, personal resources, shows that your sacrifices may very well have their rewards, in money or other ways. What you hold back will make other things prosper. The sextile to the 10th House says about the same. Your career demands sacrifice, so these can be to your advantage in some cases.

© Stefan Stenudd
The planets
The Zodiac
The Houses
The aspects