Arabic parts, also called lots, are calculated points on the ecliptic. They are not planets, houses, or fixed stars. Each lot is produced by a simple arithmetic formula from the longitudes of two or three chart factors, and it marks a specific area in which the forces of those factors become concrete. If a planet describes a mode of action, a sign describes its quality, and a house describes its field, a lot shows the address where those layers meet.
> In short. A lot is an arc between two chart points, projected from a third. The two principal lots are Fortune and Spirit. They are built from the Ascendant and the distance between the Sun and Moon, and their formulas reverse between day and night charts. A lot is read through its sign, house, ruler, and aspects; it does not replace planets and houses, it sharpens them.
The terminology is fluid. English sources say lots, parts, and Arabic parts; other languages use equivalent terms such as "shares" or "portions." All of them mean the same thing: a point produced by a formula, not an observed celestial body. The word "Arabic" is historical rather than ethnic. The technique is older than Arabic astrology; the name stuck because medieval Arabic and Persian scholars preserved and expanded the older material.
A lot has no light and no nature of its own in the way a planet does. It does not "act" by itself. It marks a place where two forces meet and shows where that meeting is directed. It therefore makes little sense to ask whether a lot is "strong" in isolation. The useful questions are: which sign rules it, which house contains it, which planets aspect it, and what condition those planets are in.
1. What the formula calculates
The general form of any Arabic part is:
Lot = A + B − C
Here A, B, and C are positions expressed as absolute ecliptic longitude from 0° Aries. Most often A is the Ascendant, while B and C are planets, luminaries, angles, or other lots. The formula projects the arc between B and C from A: first measure the distance from C to B in the order of the signs, then add that distance to A.
Geometrically, the lot is the reflection of C across the midpoint of the arc A–B. If M = (A + B) / 2, then Lot = 2M − C. This is worth remembering: a lot is not the midpoint between two planets, and it is not a planet "strengthened" by another planet. It is a point symmetrical to the third factor across the midpoint of the first two. That is why a lot can fall in a sign that none of its three components occupies.
The formula uses longitude only. Latitude, declination, and distance from Earth are irrelevant: the lot lies on the ecliptic, not in three-dimensional space. Use longitudes from one ephemeris and one coordinate system. Parallels and contraparallels do not apply to a point defined purely by zodiacal longitude.
A lot is not an independent indicator. It is fully derived from its components. If the formula contains the Ascendant, Sun, and Moon, the lot adds no new information about those three points; it translates their relationship into a new vantage point. A lot is therefore not a "third planet" and not an autonomous object that "influences" the chart. Its value is different: it makes explicit a theme that would otherwise be scattered across several factors.
Three layers are useful: the core (Fortune and Spirit), the extended set (Eros, Necessity, Courage, Victory, Nemesis, marriage), and the later lists, whose formulas often differ between sources.
2. Day and night charts
The key fork in the whole system is the determination of sect. A day chart is one in which the Sun is above the horizon; a night chart is one in which the Sun is below it. In most house systems this corresponds to the Sun in houses VII–XII for a day chart and in houses I–VI for a night chart. More precisely, judge the Sun's actual position relative to the horizon: if it lies between the Ascendant and the Descendant through the Midheaven, it is above the horizon; if it lies between the Descendant and the Ascendant through the IC, it is below.
Why does this matter? Because the formulas of Fortune and Spirit reverse. In a day chart:
Fortune = Asc + Moon − Sun
Spirit = Asc + Sun − Moon
In a night chart:
Fortune = Asc + Sun − Moon
Spirit = Asc + Moon − Sun
Notice that the day formula for Fortune is exactly the night formula for Spirit, and vice versa. This is not a coincidence or a typo. If an astrologer uses the wrong sect, the result is not a random point: it is the other lot. Fortune lands where Spirit should be, and Spirit lands where Fortune should be. The error is easy to detect: compute both lots under both formulas and see whether the result matches the logic of the chart.
The reversal reflects the classical idea that the Sun is the leading luminary in a day chart and the Moon is the leading luminary in a night chart. Fortune is the lot of the Moon and the body; Spirit is the lot of the Sun and the mind. In a day chart the solar arc is projected from the Ascendant; in a night chart the direction reverses so that the relationship between leader and follower is preserved in terms of sect. Different authors explained this differently, but the formula itself is a convention, not a deduction from physics.
3. Calculation step by step
Most calculation errors come from sign arithmetic, sect, and normalization rather than from difficult mathematics. Fix the order of operations.
Step 1. Convert every position to absolute longitude. Longitude runs from 0° to 360° from 0° Aries; each sign occupies 30°.
| Sign | Start | End |
|---|---|---|
| Aries | 0° | 30° |
| Taurus | 30° | 60° |
| Gemini | 60° | 90° |
| Cancer | 90° | 120° |
| Leo | 120° | 150° |
| Virgo | 150° | 180° |
| Libra | 180° | 210° |
| Scorpio | 210° | 240° |
| Sagittarius | 240° | 270° |
| Capricorn | 270° | 300° |
| Aquarius | 300° | 330° |
| Pisces | 330° | 360° |
The conversion is: absolute longitude = sign number × 30 + degree within the sign, where Aries = 0, Taurus = 1, Gemini = 2, and so on. For example, 12° Leo = 4 × 30 + 12 = 132°; 20° Cancer = 3 × 30 + 20 = 110°; 5° Taurus = 1 × 30 + 5 = 35°.
Step 2. Determine sect. Check whether the Sun is above the horizon. Use the day formulas in a day chart and the night formulas in a night chart. Do not infer sect from the Sun's sign.
Step 3. Substitute into the formula. Add and subtract absolute longitudes, not degrees within signs. Adding "12° Leo" and "5° Taurus" as 12 + 5 produces a meaningless number.
Step 4. Normalize the result. If the result is 360° or more, subtract 360°. If it is negative, add 360°. A result of exactly 360° is 0° Aries.
Step 5. Convert back to sign and degree. Divide by 30. The whole-number part is the sign index (0 = Aries, 1 = Taurus, ..., 11 = Pisces); the remainder is the degree within the sign. For example, 57° = 1 × 30 + 27, or 27° Taurus. If you work with minutes, keep them: 57.5° = 27°30′ Taurus.
Step 6. Check the result. For Fortune and Spirit there is a useful identity: Fortune + Spirit = 2 × Asc (mod 360°). If the sum does not match, you have either the wrong sect or an arithmetic error.
A worked calculation
Take a simple day chart: Asc 0° Aries, Sun 10° Cancer, Moon 20° Libra.
| Factor | Position | Absolute longitude |
|---|---|---|
| Asc | 0° Aries | 0° |
| Sun | 10° Cancer | 100° |
| Moon | 20° Libra | 200° |
Fortune = 0 + 200 − 100 = 100° = 10° Cancer. Spirit = 0 + 100 − 200 = −100°; add 360° to get 260° = 20° Sagittarius. Check: 100 + 260 = 360 = 2 × 0.
A lot inherits the precision of its input: use one ephemeris, one zodiac, and one house system, and do not calculate the lot in one system while reading its house in another.
4. The Lot of Fortune
The Lot of Fortune is the best known and most widely used lot. In a day chart it is Asc + Moon − Sun; in a night chart it is Asc + Sun − Moon. Its nature is lunar: body, health, material circumstances, and what a person receives at birth, including resources, environment, and living conditions.
The word "fortune" here does not mean a pleasant emotional state. It means one's portion in the old sense: what has fallen to one's lot, the quality of bodily and material life. The Lot of Fortune shows where a person can most easily lean on circumstances, where resources come from, and in which area life feels stable. It does not promise pleasure and does not cancel difficulty; it indicates a source of support.
In the classical tradition the Lot of Fortune is sometimes called a "second Ascendant." This does not mean it equals the Ascendant in power. It means that a separate system of houses can be built from it to read the body, health, property, and everyday conditions. Beginners should first read the lot in the ordinary houses and only later experiment with "houses from Fortune."
Fortune is especially sensitive to the Moon. If the Moon is in the same sign as the lot, or aspects it, the theme of body and resources receives support. If the Moon is afflicted, the lot may indicate unstable conditions and a need to care for health and daily life. But no conclusion should rest on one factor: the condition of the Moon, the lot's ruler, and the houses they occupy matter more than the mere fact of an aspect.
Sign quality adds colour. Fortune in Taurus leans on material stability, sensual pleasure, accumulation, and the body; resources arrive slowly but reliably. Fortune in Scorpio leans on shared resources, crisis, depth, other people's money, and transformation. Fortune in Aquarius leans on freedom, networks, ideas, collective projects, and unusual income. The sign shows how, the house where, the ruler who acts, and the aspects under what conditions.
5. The Lot of Spirit
The Lot of Spirit is the second principal lot. In a day chart it is Asc + Sun − Moon; in a night chart it is Asc + Moon − Sun. Its nature is solar: mind, will, intention, action, and vocation. If Fortune describes what is given, Spirit describes what a person does with it: choice, motivation, direction of effort, and the manner of self-realization.
In modern practice Spirit is often tied to career, but the classical meaning is broader. It is the "leading principle": what a person regards as central, what they serve, where their attention is directed. It can appear in profession, creativity, beliefs, education, or public role. Read it not only through the 10th house but also through the 9th (beliefs, education), the 3rd (speech, learning, communication), and the 1st (personal initiative).
Fortune and Spirit form a pair. Their relationship is exact: Fortune + Spirit = 2 × Asc. They are therefore always symmetrical about the Ascendant. If Fortune is 30° from the Ascendant in one direction, Spirit is 30° in the other. They are not generally opposite: the distance between them is twice their distance from the Ascendant and can range from 0° to 180°. They form an opposition only when the Ascendant lies exactly halfway between them on the axis.
At the New Moon, when Sun and Moon share the same longitude, both lots fall on the Ascendant. At the Full Moon, when the Moon is opposite the Sun, both fall on the Descendant. In intermediate phases they separate on either side of the Ascendant. This is a useful visual check: if Fortune and Spirit are far from the Asc–Desc axis, the Moon is neither new nor full, which is entirely normal.
When Fortune and Spirit contradict each other, do not rush to choose the "right" lot. Describe both poles and find the planet that links them: a ruler, an aspect, a shared dispositor. That planet often shows how the person reconciles the contradiction.
6. The other major lots
Beyond Fortune and Spirit, the classical tradition distinguishes five lots tied to the planets. Together they form a set of seven.
| Lot | Planet | Day formula | Night formula | Main theme |
|---|---|---|---|---|
| Fortune | Moon | Asc + Moon − Sun | Asc + Sun − Moon | body, health, resources, living conditions |
| Spirit | Sun | Asc + Sun − Moon | Asc + Moon − Sun | mind, will, action, vocation |
| Eros | Venus | Asc + Venus − Spirit | Asc + Spirit − Venus | desire, attraction, love |
| Necessity | Mercury | Asc + Fortune − Mercury | Asc + Mercury − Fortune | constraint, duty, opponents, narrow passages |
| Courage | Mars | Asc + Fortune − Mars | Asc + Mars − Fortune | resolve, conflict, force, competition |
| Victory | Jupiter | Asc + Jupiter − Spirit | Asc + Spirit − Jupiter | success, faith, support, allies |
| Nemesis | Saturn | Asc + Fortune − Saturn | Asc + Saturn − Fortune | loss, retribution, limit, humility |
Notice the pattern: the lots of Venus and Jupiter are built from Spirit, while the lots of Mercury, Mars, and Saturn are built from Fortune. In classical logic the benefics are linked to intention and soul, while the malefics and neutral Mercury are linked to body, fate, and circumstance. This is not a moral ranking of the planets but a structural principle.
The formulas for Eros, Necessity, Courage, Victory, and Nemesis use the Fortune and Spirit already calculated for the same chart and the same sect. Do not substitute a day Fortune into a night formula or vice versa. Determine sect first, then compute Fortune and Spirit, then use them as components of the remaining lots. For some of these lots, sources differ on the order of terms; the table follows one classical convention, and the key is to apply it consistently.
Read these lots through their sign, house, ruler, and aspects. Eros shows desire; Necessity shows constraint; Courage shows where one fights; Victory shows support; Nemesis shows the limit. None of them is a verdict on its own.
The lot of marriage
The lot of marriage is among the most requested and least standardized. In the classical pair it uses Venus and Saturn: for a male chart Asc + Venus − Saturn, for a female chart Asc + Saturn − Venus. This pair is usually not reversed by sect. Later compilations offer other variants, from Mars and Venus to the cusp of the 7th house. Choose one convention, state it, and do not mix several formulas in one analysis.
Read the marriage lot with the 7th house, its ruler, Venus, and Mars. It does not show "the person you will marry" but the conditions and quality of union: how partnership is understood, what is expected from marriage, and which themes will be active. In synastry, check whether one partner's marriage lot falls on the other's planets or angles, but do not draw a conclusion from a single contact.
Later lists
The later lists are vast: parents, children, siblings, inheritance, travel, illness, trade, war, harvest, friends, enemies. Formulas differ between sources, and some lots duplicate one another under different names. Do not use a lot whose formula you cannot verify, and do not add more than one or two narrow lots to an analysis. If a topic is already well described by a house and its ruler, an extra lot often adds noise rather than insight.
Check formulas for degeneration: if a formula reduces to an angle or an already known point, it is not an independent lot.
7. House and sign
After calculation, answer two questions: which house contains the lot and which sign. These are different layers and should not be mixed.
In a whole-sign system the house is determined by the sign: if the Ascendant is in Leo, Leo is the 1st house, Virgo the 2nd, Libra the 3rd, and so on. In a quadrant system the house is determined by the cusps: the lot belongs to the house between whose cusps it falls. Both approaches are valid, but they must not be combined.
| House | Field | Fortune | Spirit |
|---|---|---|---|
| 1 | identity, body, initiative | vitality, personal resources | personal will, capacity to act |
| 2 | money, values, resources | income, property, self-support | skills, speech, self-worth |
| 3 | communication, learning, local circle | income from writing and teaching | thinking, learning, exchange of ideas |
| 4 | home, family, roots, property | family property, work from home | inner foundation, privacy |
| 5 | creativity, children, pleasure | income from creativity and entertainment | self-expression, play, teaching |
| 6 | work, health, service | daily labour, health, craft | skill, discipline, service |
| 7 | partnership, marriage, opponents | partner's resources, clients | negotiation, public dealings |
| 8 | shared resources, crisis, inheritance | inheritance, other people's money, insurance | research, transformation, depth |
| 9 | travel, education, beliefs | income from abroad, publishing | philosophy, long journeys, teachers |
| 10 | career, reputation, authority | public success, material rewards | vocation, ambition, social role |
| 11 | friends, networks, hopes | patrons, collective resources | social ideals, group projects |
| 12 | solitude, institutions, the hidden | hidden resources, care, institutions | inner life, retreat, spirituality |
These are layers, not fixed verdicts. Fortune in the 12th does not mean misfortune; it can indicate resources that come through solitude, institutions, care for others, or work behind the scenes. Spirit in the 12th can indicate a vocation connected with spirituality, research, isolation, or service. Context matters more than the table.
Angular houses (1, 4, 7, 10) make a topic visible and effective; succedent houses (2, 5, 8, 11) give stability and resource; cadent houses (3, 6, 9, 12) make a topic less public, more preparatory, or more hidden. But a lot in a cadent house with a strong ruler can manifest more clearly than a lot in an angular house with an afflicted ruler.
8. The ruler of the lot
The ruler of the sign containing the lot is a key interpretive figure. It shows who or what acts in the lot's topic: a specific planet, its house, its condition, and its connections. Without the ruler, the reading remains superficial.
| Sign | Ruler |
|---|---|
| Aries | Mars |
| Taurus | Venus |
| Gemini | Mercury |
| Cancer | Moon |
| Leo | Sun |
| Virgo | Mercury |
| Libra | Venus |
| Scorpio | Mars |
| Sagittarius | Jupiter |
| Capricorn | Saturn |
| Aquarius | Saturn |
| Pisces | Jupiter |
These are the traditional rulers. Modern practice sometimes uses the outer planets for Aquarius, Pisces, and Scorpio, but classical lot work is more consistent with the traditional rulers. The important point is not to mix systems.
Judge the ruler by its dignity in the sign (domicile, exaltation, detriment, fall), its house, its sect, its retrograde state, its combustion (within 8.5° of the Sun), and its aspects. A ruler in its own sign and in an angular house acts confidently; a ruler in detriment, fall, or combustion struggles to deliver.
If the ruler is in the same sign as the lot, the topic is "at home": it is easier to realize. If the ruler is in the opposite sign, the topic may depend on other people or require balance. If the ruler is in aversion to the lot, the topic may be disconnected from its source: the person has to build the connection consciously.
The first link of the dispositor chain often shows who really governs the topic; in a quadrant system, the ruler of the lot's sign and the ruler of its house cusp may differ.
9. Aspects
A lot is a point, not a body. Strictly speaking, it does not cast aspects and does not aspect planets. Aspects are considered in one direction: from a planet to the lot. A planet that aspects the lot colours it with its nature and condition. Some practitioners also consider aspects between lots, but that is a secondary layer.
Use tighter orbs for lots than for planets. A conjunction within 1–3° is strong, 3–5° moderate, and beyond 5° weak. For opposition, square, trine, and sextile, 3–5° is usual. In the whole-sign tradition, aspects are judged by sign and no orb is needed; in degree-based practice, the orb depends on the school. Do not stretch the orb to 10–12°, or almost every planet will be "in aspect" to every lot.
A conjunction (0°) is the strongest contact: the planet imposes its topic on the lot. Opposition (180°) creates tension and the need for choice. Square (90°) brings friction and effort. Trine (120°) brings support and ease. Sextile (60°) offers an opportunity that requires action.
Jupiter and Venus are benefics; Mars and Saturn are malefics; Mercury is neutral. The benefic of the sect (Jupiter by day, Venus by night) supports the lot most reliably; the out-of-sect benefic helps less consistently. The out-of-sect malefic (Mars by day, Saturn by night) is usually more disruptive; the in-sect malefic (Saturn by day, Mars by night) can provide discipline and constructive pressure. "Malefic" does not mean "bad": Saturn aspecting Fortune can indicate thrift and a late but solid prosperity; Mars can supply energy to overcome obstacles. The condition of the planet matters.
If the lot's ruler aspects the lot, the topic is connected to its source and easier to realize. If the ruler is in aversion, the topic may be disconnected: the person must seek the resource outside or build it personally.
10. Reading order
A lot is a lens, not a verdict. It shows where to look but does not replace the analysis of planets, houses, and aspects.
1. Check the birth time and sect. Without an accurate time and a correct day/night judgment, the calculations are unreliable.
2. Compute Fortune and Spirit. This is the core. Check that their sum equals 2 × Asc.
3. Locate each lot by sign and house. House is the field; sign is the quality.
4. Find the ruler of the sign. Assess its dignity, house, sect, retrogradation, and combustion.
5. Check aspects from planets. Start with conjunctions, then oppositions, squares, trines, and sextiles. Pay special attention to the ruler and the luminaries.
6. Check the relation to angles and to the house of the topic. A lot on an angle or in the topic's house carries extra weight.
7. Cross-check the relevant house and its ruler. For marriage, the 7th house and Venus; for career, the 10th and the MC; for money, the 2nd and its ruler.
8. Synthesize. Describe strengths, weaknesses, conditions, and possible scenarios. Do not draw a conclusion from one factor.
Priorities are simple. Fortune and Spirit first; then one or two specific lots for the question. If two lots contradict each other, do not choose the "right" one: describe the tension. If a lot is strong but its house is weak, the topic may be a resource that is hard to manifest; if the lot is weak but the house is strong, other factors may support the topic.
11. Worked examples
Example 1: a day chart
Take a teaching chart: Asc 12° Leo, Sun 20° Cancer, Moon 5° Taurus, Venus 25° Taurus. The Sun is in the 12th house, above the horizon, so the chart is diurnal.
| Factor | Position | Absolute longitude |
|---|---|---|
| Asc | 12° Leo | 132° |
| Sun | 20° Cancer | 110° |
| Moon | 5° Taurus | 35° |
| Venus | 25° Taurus | 55° |
Fortune = 132 + 35 − 110 = 57° = 27° Taurus. Spirit = 132 + 110 − 35 = 207° = 27° Libra. Check: 57 + 207 = 264 = 2 × 132.
In whole signs from Leo, the houses run Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer. Fortune is in the 10th house, Spirit in the 3rd.
Venus rules both lots, since it rules Taurus and Libra. Venus is at 25° Taurus, in the 10th house, in its own sign, 2° from Fortune. This is a strong placement: the ruler is in its own sign, in an angular house, and conjunct the lot. The material and public theme is supported: resources come through profession, reputation, and public activity, while Venus adds values, taste, relationships, and money.
Spirit is in the 3rd house, in Libra, ruled by the same Venus. But Venus is 152° from Spirit and does not form a classical aspect. Fortune and career are directly connected through Venus, while mind and action (Spirit in the 3rd) are connected to Venus only through rulership. Communication, learning, and the local circle can become a bridge to career, but the bridge has to be built consciously.
Fortune and Spirit are 150° apart (Taurus–Libra), in aversion by sign. They are symmetrical about the Ascendant (75° on each side), but they do not "see" each other. This is a good example of symmetry without opposition. The bodily-material side and the mental-volitional side develop in different registers and need deliberate integration.
Example 2: a night chart
Take another teaching chart: Asc 20° Scorpio, Sun 15° Gemini, Moon 22° Cancer, Venus 10° Libra, Jupiter 27° Sagittarius. The Sun is after the Descendant (20° Taurus) and before the Ascendant, so it is below the horizon; the chart is nocturnal.
| Factor | Position | Absolute longitude |
|---|---|---|
| Asc | 20° Scorpio | 230° |
| Sun | 15° Gemini | 75° |
| Moon | 22° Cancer | 112° |
| Venus | 10° Libra | 190° |
| Jupiter | 27° Sagittarius | 267° |
Fortune = 230 + 75 − 112 = 193° = 13° Libra. Spirit = 230 + 112 − 75 = 267° = 27° Sagittarius. Check: 193 + 267 = 460; 460 − 360 = 100 = 2 × 230 (mod 360).
In whole signs from Scorpio, the houses run Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra. Fortune is in the 12th house, Spirit in the 2nd.
Venus rules Fortune. It is at 10° Libra, in the 12th house, in its own sign, 3° from Fortune. The ruler is in its own sign and conjunct the lot, so the topic is supported, but the 12th house makes it hidden, private, connected with institutions, care, solitude, or work behind the scenes. This is not a "bad" Fortune; it is a resource that is not displayed.
Jupiter rules Spirit. It is at 27° Sagittarius, in the 2nd house, in its own sign, exactly on Spirit. This is a very strong placement: mind, will, and action are directed toward resources, values, speech, and learning; Jupiter in its own sign gives growth, support, faith, and the ability to turn knowledge into material.
One chart, two formulas
Return to the first example: Asc 12° Leo, Sun 20° Cancer, Moon 5° Taurus. The chart is diurnal. If the night formulas are used by mistake, the lots do not become random points; they swap places.
| Lot | Day formula (correct) | Night formula (error) |
|---|---|---|
| Fortune | 27° Taurus, 10th house | 27° Libra, 3rd house |
| Spirit | 27° Libra, 3rd house | 27° Taurus, 10th house |
This follows from the identity: the day Fortune equals the night Spirit, and the day Spirit equals the night Fortune. If sect is uncertain, compute both versions and look for the mirror pair. Then check the Sun's actual position and choose the correct column. The example also shows why sect cannot be inferred from the Sun's sign: the Sun in Cancer says nothing about day or night by itself.
12. Timing and limits
Lots are used outside the natal chart as well. In prediction, horary, and synastry they play a supporting role.
Transits. A transiting aspect to a natal lot can activate its topic. A conjunction is the most visible contact: transiting Jupiter on Fortune may open a period of resource growth; transiting Saturn on Fortune may bring restriction and a review of material conditions. Use tight orbs: an exact conjunction within 1° is the peak, and the influence lasts while the planet is within 1–2°. The quality depends on the planet's nature and condition. A lot only specifies where the event is likely to appear; it should not be read apart from transits to planets and angles.
Zodiacal releasing. This is a separate time-lord technique in which periods are counted from Fortune and Spirit. Fortune is used for body, health, property, and everyday conditions; Spirit for action, career, and reputation. Releasing has its own rules; do not imitate it by simply moving lots through the years.
Horary. In a horary chart, lots can be calculated from the question's Ascendant and luminaries. They may clarify the topic, but they do not replace the main significators: the Ascendant and its ruler, the Moon, the house of the question, and its ruler. If a lot contradicts the main significators, trust the main ones. In synastry, one partner's lots falling on the other's planets or angles indicate a resonance of themes; this is a supplementary layer, not proof of compatibility.
The method has limits. A lot built from the Ascendant shifts by about 1° every four minutes; with an uncertain birth time it may move several degrees and sometimes change sign. A lot is derived, not independent: it adds no new information about the Sun, Moon, and Ascendant, but reframes their relationship. The same lot can fall in different houses in whole-sign and quadrant systems. The aspect method changes the conclusion: whole-sign aspects are judged by sign, degree-based aspects by orb. A lot has no energy of its own; a transit to a lot is a planet's contact with a point, not the lot's motion. And more lots do not mean more accuracy: 3–7 lots for a specific question is a sensible limit.
13. Common mistakes
1. Wrong sect. Using the day formula in a night chart swaps Fortune and Spirit. Check the Sun's position relative to the horizon, not only its sign.
2. Inferring sect from the Sun's sign. The Sun in Aries can be diurnal or nocturnal; the sign does not determine sect.
3. Sign arithmetic. Do not add "12° Leo" and "5° Taurus" as 12 + 5. Convert everything to absolute longitude.
4. Forgotten normalization. A result above 360° or below 0° is an intermediate value. Bring it back into the 0–360° range.
5. Mixing zodiacs. If the Ascendant and planets are tropical, the lot is tropical. Do not insert sidereal longitudes into a tropical formula or vice versa.
6. Mixing house systems. Determine the lot's house in the same system used to read the chart.
7. Treating a lot as a planet. A lot has no light, does not aspect, and does not "influence" by itself. Aspects go from planets to the lot, not the other way round.
8. Ignoring the ruler. A lot without its ruler is half the information.
9. Overloading the chart. Five to seven lots is a practical limit for one question. Twenty lots create noise and invite confirmation bias.
10. Mixing marriage formulas. Choose one convention (for example, Venus–Saturn) and do not combine it with Mars–Venus or 7th-cusp variants in one analysis.
11. Assuming Fortune and Spirit are always opposite. They are symmetrical about the Ascendant, not necessarily opposite. Their sum is 2 × Asc.
12. Using wide orbs. If everything within 10–12° counts as an aspect, every planet is linked to every lot. Use 1–5° for lots.
13. Ignoring the condition of the aspecting planet. A benefic in detriment, combustion, or retrograde motion may not deliver the promised support.
14. Checklist
- [ ] Birth time is known and its uncertainty is assessed.
- [ ] Sect is determined from the Sun's position relative to the horizon.
- [ ] All positions are converted to absolute longitude.
- [ ] Three to seven lots are selected for the question.
- [ ] Fortune and Spirit use the correct formula; the sum 2 × Asc is verified.
- [ ] Each lot has a sign and a house in the chosen system.
- [ ] The sign ruler is identified; its dignity, house, sect, retrograde state, and combustion are assessed.
- [ ] Planetary aspects to the lot are checked with a reasonable orb.
- [ ] The lot's relation to angles and to the house of the topic is checked.
- [ ] The relevant house, its ruler, and natural significators are cross-checked.
- [ ] Strengths, weaknesses, and mixed testimony are described; no conclusion rests on one factor.
- [ ] The limits of the method and the level of confidence are stated.
15. Conclusion
Arabic parts are not magical points and not a substitute for planets. They are a disciplined way to translate the relationships among the luminaries, planets, and angles into a concrete topic. The Lot of Fortune shows where a person can lean on circumstances; the Lot of Spirit shows where will and action are directed. The remaining lots refine specific areas: desire, constraint, courage, victory, limit, and marriage.
The system rewards care: correct sect, clean longitude conversion, a consistent house and aspect method, and resistance to overloading the chart. Begin with the two principal lots on charts with known birth times, then add one specific lot for a specific question. A lot is not a separate fate; it is an angle of vision that makes visible a side of the chart that would otherwise remain in shadow.
Prepared by the [Astrobot](https://astrobot.chat) team. Based on the classical and modern astrological tradition.
endant, Moon, houses and aspects, monthly theme synthesis, timing by lunar houses and phases, comparison with natal and solar returns, limitations and common mistakes.