Lot of Necessity

Sect reverses the arc: the day formula applies when the Sun is above the horizon, the night formula when it is below.

Traditional signification

Derived from Fortune and Mercury. Traditionally associated with constraint, enmity, and circumstances that limit or compel.

Compute your Lot of Necessity

The lots calculator computes all seven Hermetic Lots from your birth data, applying the correct sect formula automatically.

Questions

What is the Lot of Necessity?

Derived from Fortune and Mercury. Traditionally associated with constraint, enmity, and circumstances that limit or compel. In Greek it is Ἀνάγκη (Ananke). The topics it addresses: constraint, obligation, things outside one's control.

How is the Lot of Necessity calculated?

By day: Ascendant + Fortune − Mercury. By night: Ascendant + Mercury − Fortune. The two formulas are mirror images, and which one applies depends on the sect of the chart - whether the Sun is above or below the horizon at birth. Getting the sect wrong swaps the formula and moves the lot to a different degree, often a different sign, so a lot quoted without a stated sect cannot be checked.

Does the Necessity lot need an exact birth time?

Yes, and this lot is more time-sensitive than a planet position. The formula is Ascendant + Fortune − Mercury by day. The Ascendant advances roughly one degree every four minutes, so an hour of uncertainty moves the Necessity lot about 15 degrees, half a sign or more. It is worse here than for the first two lots, because Fortune is itself computed from the Ascendant: the same error enters the calculation twice, once directly and once through that term. A lot built on another lot cannot be steadier than the lot underneath it.