Birthsign

A passive influence conferred by the celestial sign under which the character was born. A birthsign is never invoked; it quietly shapes the character, strengthening the aptitudes it favours and weakening others.

A birthsign is a standing Mystery the character carries: it adjusts the Effective Mastery Level of the skills it governs — a bonus to those the sign favours, a penalty to those it hinders. It is fixed at the hour of birth and carried for life; it is never tested, never spent, and never chosen. Like every Mystery, it is unavailable while the character carries Aural Shock.

The six elements. A sign does not name skills one at a time. The Astrokýklos — the wheel of signs — divides all human aptitude into six elements, and a sign’s whole substance is where it stands in each. A skill belongs to an element by its kind, and each element also claims any mystical skill of its own name.

The modifiers run in steps of five, between +15 and −15, and an element a sign does not touch is left alone. Every sign’s six modifiers sum to zero — it favours exactly as much as it hinders — and it either peaks and troughs at one element each (+15 and −15) or spreads that same weight across two elements each way (+10 and −10).

The wheel. Twelve signs stand on the wheel — Arnos the Ram, Bourax the Ox, Diplos the Twins, Chelyx the Tortoise, Thyron the Gate, Korith the Helm, Stathmos the Balance, Kentros the Goad, Belos the Lamp, Tragyx the Stag, Nalos the River, and Opsar the Fish — each giving way to the next around the year.

Births on a threshold: the cusp. A character born as one sign gives way to the next carries both, and the rule for reading two signs together is a single one:

For each element, take the better of the signs the character carries. Modifiers from two signs are never added.

So a birth on the threshold of Arnos and Bourax takes Earth at +15 from the Ram and Metal at +10 from the Ox, and where Arnos hinders Air at −15 the Ox softens it to −10. A cusp is not a weaker sign, nor a thirteenth kind of sign — it is a birth read twice.

Because the better of two always applies, a cusp comes out ahead of either neighbour alone: its six modifiers sum to +15 rather than zero, it still peaks at +15, and it troughs no lower than −10. That surplus is what being born on a threshold is — the character is claimed by two influences and shortchanged by neither.

More than two. Nothing in the rule stops a GM from granting a third sign, or more, for a portent or a strange nativity — the same “take the better” reading applies, and each further sign can only raise an element, never lower it. Understand that the surplus compounds: a character under three neighbouring signs outdoes any cusp, and one under the whole wheel would stand at +15 in everything. One sign is the ordinary birth and two the threshold; beyond that is a deliberate GM choice, not a natural one.

Reading a sign — a stranger’s, or a newborn’s — is the work of Astrology, which needs the hour and place of birth to cast a natal chart.