The 4 triplicities are a means of extracting more information and insight from the geomantic shield chart. If you are familiar with astrology, you might think this relates to the triplicities in astrology which deal with a division of signs into the 4 elements. This is not connected however. In some ways this makes a good transition from the shield chart and it’s interpretation to interpreting the house chart. 

The 4 triplicities are achieved by taking the first twelves figures and dividing them into four groups of three. Thus why there are four triplicities. Each triplicity either has 2 mothers or 2 daughters and a niece, and are arranged similarly to how the two witnesses and judge are set up. You read these triplicities similarly to the two witnesses and judge, but relating to specific areas relating to the client.
The 1st triplicity is made up of Mothers 1 and 2, and the 1st niece. This triplicity gives information relating directly to the client and their personal make up. It could include appearance, health, general outlook and personality.This is also why the 1st Mother gives indications to the intent or mindset of the client and if the figures of Cauda Draconis or Rubeus show up, those indicate that the client is engaged in deception. With Cauda Draconis it is self deception, whereas with Rubeus, it indicates it could be to deceive the reader.

The 2nd triplicity consists of the 3rd and 4th mothers and the 2nd niece. This indicates events and direct influences acting on the client at the time of the reading. If the client isn’t engaging in deception, this would give indication why the client is seeking a reading at this time.

The 3rd triplicity consists of the 1st and 2nd Daughters and the 3rd Niece. This triplicity indicates the personal and private environment of the client. Parents, siblings, spouses, roommates,and lovers and close personal friends are indicated here, as is the home environment, interactions of immediate family, and personal interactions of the client in an intimate environment. 

The 4th triplicity indicates public relations and public environments. The workplace, co workers, casual friends and acquaintances, chance meetings, business dealings with non-family members, and interactions with government and its representatives from judges and politicians (or in the past kings and princes) but also judges, the police, lawyers, neighbors, bureaucrats etc… but also the places where these interactions may happen like government buildings, markets, parks, etc… 

These four houses obviously help in greatly expanding the information you can convey to the client in the reading just from the shield chart. With the judge and witnesses, way of points, sum of points, Sentence and the four triplicities you could give a very full reading to any client, and if signs repeat themselves within the triplicities, and the judge of witnesses and sentence could show connections between the question and where help or opposition or underlying causes can be shown.

Example
In this chart the client is asking about their current illness.

The judge is Fortuna Major, a fortunate sign. It doesn’t indicate that the client will recover completely, but in this case it will not happen quickly. As the Right Witness is Populus, showing that the client is open to anything. The Left Witness is again Fortuna Major, showing that the coming influence will assist the client in their recovery. 

In looking at the triplicities, in the first triplicity we see Fortuna Minor, Conjunctio and Amissio. As this is about the client, it shows that they tend to rush (fortuna minor) and perhaps not take care of their health, which caused them to meet with the source of infection (Conjunctio) causing the loss of their health (Amissio).

The Second Triplicity is made up of Albus, Laeticia, and Amissio. This shows the current condition of the client. Albus indicates they are resting, as it is a figure of rest and peace. Laetiticia indicates that the client is in high spirits and looking to the future when they are well, a generally positive thing, but the end result is again Amissio or loss. The client’s condition is not improving as they would like.

The third Triplicity is made of Carcer, Fortuna Minor, and Acquisitio. This is about the client’s immediate environment. Carcer (Prison) indicates that they are and recently have been isolated. Maybe they live alone, or have no one to care for them directly. Fortuna Minor indicates some help may come his way, if they only ask or just accept it. Acquisitio indicates that he may gain something, and that perhaps it may see improved recovery from the possible assistance.

The fourth Triplicity is made of Conjunctio, Populus, and Conjunctio again. As Conjunctio was present in the first house, this suggests that by repeated exposure to the public, there is a chance of another infection. Maybe the client should be careful and not exposes themselves to crowds of people in order to avoid re-infection.