Chris Brennen’s essential dignities and debilities.
Beginning with Aries , since this is the season, say your Mars sign is in Aries and if you’re born at nighttime your Triplicity lord (ruler) is Jupiter in a night chart.
A night chart is when the sun is below the horizon of the natal chart & a day chart is when it’s below. Usually corresponding to being born in the daytime or nighttime
Therefore it lessens the malefic impact of Mars, using Hellenistic format in your astrology calculator it will show the bounds and if they’re within Venus or Jupiter this is fortune and again lessens Mars effects.
Above you can see how the houses show the bounds here is using astroseek , traditional chart- whole sign
The Decans divide each of the 12 signs into thirds
Decans are 36 parts and are 10 degrees
So say your moon is in 7 degrees Taurus , it’s Decans is the 1st because it’s under 10 degrees , therefore it’s under the rulership of mercury here, bringing those themes