Ogham Fidchast (歐甘字母神諭)

The Tree-Alphabet — a Celtic Letter-Oracle on the Bríatharogam Kennings

Overview

Carved along the edges of standing stones across early-medieval Ireland is a script of tally-like strokes: Ogham, the oldest form of written Irish. Its twenty letters — the feda — are not named for sounds alone but for things in the world, and grouped into four families of five. Medieval scholars recorded, for each letter, three terse two-word 'kennings' — the Bríatharogam — riddling glosses like 'highest of trees' for oak, 'the making of peace' for ash, 'hardest going by night' for the fearful whitethorn. Those kennings are what askTIAN reads. Ask a question and the oracle draws a fid — or a three-few spread of past, present and what is coming — and returns its name, its tree, its three medieval kennings and a reflective sense. It is candid throughout: the systematic oracle is largely modern, but it is anchored on the authentic letters and kennings, not on Robert Graves' 20th-century 'Tree Calendar' — and medieval Irish literature does, once, show ogham cast for divination, when the druid Dalán cuts four wands of yew, marks them with ogham and casts them to find the stolen Étaín.

Origin & history

Ogham (ogam) survives in some four hundred stone inscriptions of the 4th to 6th centuries CE, chiefly in Ireland and in Irish-settled parts of Wales, Scotland and the Isle of Man, and in a rich manuscript tradition thereafter. The letters are grouped into four aicmi ('families'), each of five, named for their first letter: Aicme Beithe, Aicme hÚatha, Aicme Muine and Aicme Ailme; five further letters, the forfeda, were added later for sounds the original score lacked. The letter-names and their kennings are set out in the Auraicept na n-Éces ('The Scholars' Primer') and the tract In Lebor Ogaim ('The Book of Ogham'), which preserve three Bríatharogam lists ascribed to legendary authorities — Morann mac Moín, Mac ind Óc (Angus) and Cú Chulainn. The definitive modern study is Damian McManus's 'A Guide to Ogam' (1991), on which askTIAN's letters, sounds and kennings are based.

askTIAN is careful to separate the authentic from the modern. Firm and medieval: the twenty feda, their arrangement into four aicmi of five, the five forfeda, the letter-names and sounds, and the three Bríatharogam kennings for each — all attested in the Auraicept. The kennings are terse translations of Old Irish, and askTIAN renders them in its own words. What is modern is the systematic use of ogham as a tarot-like oracle: there is little evidence the medieval kennings were meant divinatorily (they were mnemonic and scholarly), and the popular 'tree oracle' owes most to Robert Graves' 'The White Goddess' (1948), whose 'Tree Calendar' askTIAN does NOT follow — it is a separate modern construction, and distinct again from the Celtic Tree Sign birthday-zodiac already in the catalogue. The one genuine medieval warrant for ogham divination is the tale Tochmarc Étaíne, where Dalán the druid casts four yew ogham-wands (the method left undescribed). And the favourable/neutral/challenging tone askTIAN reports for a summary score is an interpretive overlay, not part of the descriptive kennings: ogham is a reflective letter-oracle, not a yes-or-no verdict.

How it works

The engine carries the twenty-five letters as a locked table — each with its name, glyph, sound, aicme, tree and the three Bríatharogam kennings, plus an interpretive one-line sense. A reading obtains a fid one of two ways. If you supply one you drew yourself — a name such as 'Beith', an Ogham glyph, or a position 1–25 — the engine reads that letter. Otherwise it draws deterministically: it seeds a mulberry32 generator from a stable hash of your question (with an optional name and date) and draws either a single fid or three distinct feda for a past/present/future spread, so the same question always yields the same draw. By default the pool is the twenty primary feda; a flag widens it to include the five forfeda. The four-aicmi structure is verified in the test suite (each family holds exactly five, in canonical order), gold anchors are locked (Beith is the first fid, birch; Iodhadh the twentieth, yew), and the draw is checked to cover all twenty. The response carries each drawn fid with its kennings, an interpretive sense, a symbolic 0–100 tone score, the honesty rails, and an optional best-effort LLM reading in five parsable sections.

Good for

Use cases

Draw a Fid

Send a question and the oracle draws one Ogham letter, returning its glyph, tree, three Bríatharogam kennings and a reflective sense — a complete structured single-fid reading with no LLM required.

A Three-Few Spread

Request count 3 and the engine draws three distinct feda for past, present and what is coming — a compact ogham spread for a reflective reading.

Read a Physical Cast

A user cuts or draws ogham fews offline and sends the letter (a name, glyph, or 1–25); the engine returns exactly that fid's kennings and sense.

Browse the Feda

Expose the full locked table — the four aicmi, the twenty feda and five forfeda, their trees and kennings — as a reference for an ogham guide or an interactive alphabet stone.

Key terms

Ogham (ogam)
The earliest form of written Irish, a score of tally-like strokes carved along an edge; some 400 stone inscriptions survive from the 4th–6th centuries CE.
Fid (plural feda)
An Ogham letter — literally 'wood' or 'tree'; the twenty primary feda are each named for a tree or thing and carry their own kennings.
Aicme
A 'family' of five feda sharing a stroke-type. The four aicmi are Aicme Beithe, Aicme hÚatha, Aicme Muine and Aicme Ailme, named for their first letters.
Bríatharogam
The medieval 'word-oracle' kennings — three two-word glosses for each fid, preserved in the Auraicept na n-Éces in lists ascribed to Morann mac Moín, Mac ind Óc and Cú Chulainn.
Forfeda
The five supplementary letters added to the original twenty for sounds the score lacked (Éabhadh, Ór, Uilleann, Ifín, Eamhancholl); askTIAN keeps them out of the default draw pool.
Auraicept na n-Éces
'The Scholars' Primer', the medieval Irish grammatical tract that records the ogham letter-names and their Bríatharogam kennings.
Tochmarc Étaíne
'The Wooing of Étaín', a medieval tale in which the druid Dalán casts four yew wands cut with ogham to find the hidden Étaín — the clearest medieval warrant for ogham divination.
Not the Tree Calendar
askTIAN is anchored on the authentic feda and kennings, NOT on Robert Graves' 20th-century 'Tree Calendar' / Celtic tree-zodiac, which is a separate modern construction.

API

The askTIAN Ogham Fidchast API reads the early-medieval Irish alphabet (ogam) as a Celtic letter-oracle, anchored on the authentic Bríatharogam kennings. Ogham has 20 primary letters (feda) in four families (aicmi) of five, plus five supplementary forfeda; each fid carries a name, sound, tree and three medieval two-word kennings preserved in the Auraicept na n-Éces (lists ascribed to Morann mac Moín, Mac ind Óc and Cú Chulainn). Ask a question and the oracle draws a fid — either an explicit fid you supply (a name like 'Beith', an Ogham glyph, or 1–25, for a live cast) or a deterministic seeded draw — as a single fid or a three-few past/present/future spread, and returns each drawn fid with its glyph, aicme, tree, the three kennings (askTIAN's own English rendering), an interpretive sense and a symbolic 0–100 tone score. The four-aicmi structure, the 20 feda in canonical order, the five forfeda, the sounds and the kennings are locked by unit test (the 4×5 aicme grouping, gold anchors Beith = first/birch and Iodhadh = twentieth/yew, three kennings per fid), along with the deterministic draw, distinct three-few spreads and full pool coverage. Anchored on Damian McManus's 'A Guide to Ogam' (1991). It is candid about scope: the feda, aicmi and kennings are attested but the English is askTIAN's own; ogham's divinatory use is chiefly modern (the one clear medieval warrant is Tochmarc Étaíne); it is explicitly NOT Robert Graves' Tree Calendar, and distinct from the Celtic Tree Sign birthday-zodiac; and the favourable/neutral/challenging tone is an interpretive overlay, not part of the descriptive kennings. It is symbolic Celtic heritage divination for reflection, not prediction and not medical, legal, or financial advice. A best-effort LLM reading is returned in five parsable sections; set interpretation:false for structured data only.

Endpoint: POST /trpc/ogham.cast — 6 TIAN Points. See the API documentation and Playground.