Degrees and approximate dates
This face begins where Libra ends and runs to ten degrees of Scorpio, so it opens the fixed water month. Placements here are not near a sign boundary at the upper end, though the lower end sits directly on one.
The Sun spends about ten days here, roughly 23 October to 2 November. That range shifts by up to a day and a half between years, which is the same reason the sign dates published in newspapers never quite agree with each other.
The opening date is the less reliable of the pair, because it is a sign boundary rather than a decan boundary and is quoted differently by different publishers even for the same year.
The schemes, and the ruler question underneath them
The Chaldean order repeats Mars, Sun, Venus, Mercury, Moon, Saturn, Jupiter through the thirty six faces from zero degrees of Aries. The count lands on Mars for the opening decan of Scorpio.
The triplicity scheme assigns water decans to Cancer, Scorpio and Pisces in order, so the first decan of Scorpio goes to Scorpio. Its ruler is Mars in traditional practice and Pluto in most modern practice, since Pluto was assigned to the sign after its discovery. So the schemes agree on the sign but the answer for the planet depends on which rulership list is in use.
Popular articles usually quote a ruler with no indication of which scheme or which rulership list produced it. That is worth knowing before comparing sources, because a disagreement about this face is more often about Pluto than about decans.
What the doubled sign is read as meaning
By triplicity nothing from Cancer or Pisces is mixed in, so the tradition reads this face as the sign shown without softening. The descriptions centre on a refusal to accept the surface account of a situation, patience in holding a position while the facts come out, and a memory for who did what. Privacy is treated as a working method rather than a preference.
Mars as face ruler is taken to add the willingness to act on what has been worked out, including where acting means conflict. Sources describe a placement that does not open a subject until it is ready to see it through, so the reading names both a long silence and a decisive move, rather than one or the other. Where the modern Pluto rulership is used, the same degrees are usually described in terms of complete change rather than sustained effort.
None of this is a claim about fortune, good or otherwise. It is what the sources read into the combination, and the condition of Mars in a real chart would alter it.
Traditional practice also used the faces as a minor dignity. A planet in its own face was reckoned slightly strengthened, which is a modest technical claim rather than the character sketch most modern decan writing offers.
Other placements, and getting the boundary right
Decans work on any point. A Moon at three degrees of Scorpio is in this face, and so is an Ascendant at eight degrees. The Ascendant is where the divisions matter most, because it moves through roughly a degree every four minutes and so separates charts sharing a birth date.
The wider context is that decans came into astrology from Egyptian star lists used to mark the hours of the night. They are old and genuine, and they are also a second-order refinement. Sign, house and aspect do the substantial work in any reading, and a decan adjusts the description afterwards.
Because a decan boundary is a degree, the check at the top computes your actual solar position from your birth date. Anyone born close to 23 October or 2 November needs that rather than a published range, and a birth at the very start of the sign may turn out to be late Libra.
Questions people ask about this
What dates are the first decan of Scorpio?
About 23 October to 2 November. The exact crossings move by up to a day and a half between years, so the opening date in particular is unreliable for anyone born right on it.
Is the ruler Mars or Pluto?
Mars under the Chaldean order. Under the triplicity scheme the decan belongs to Scorpio, so the ruler is Mars traditionally and Pluto in most modern writing. The difference comes from the rulership list, not from the decan system.
Does the first decan make someone more Scorpio?
That is the traditional claim, since the triplicity scheme mixes in nothing from the other water signs. It remains an interpretation, and this page treats it as one rather than as a measured effect.
What are decans originally?
Thirty six divisions descended from Egyptian star lists, where groups of stars marked hours of the night. The planetary rulerships were attached later, once the divisions had been mapped onto the zodiac signs.
Can I use this for my rising sign?
Yes. A Scorpio Ascendant in the first ten degrees sits in this face, and many practitioners read the Ascendant decan first because the rising degree changes fastest through the day.
Why do decan descriptions vary so much online?
Two assignment schemes are in circulation, modern and traditional rulerships differ for Scorpio, and few articles state which they used. Naming the method resolves most of the apparent contradictions.