The claim that runic divination is an ancient Germanic practice rests almost entirely on one paragraph written around the year 98, and the paragraph does not say what it is asked to say.
Germania 10
Tacitus describes a Germanic method of consulting the lots. A branch is cut from a fruit-bearing tree and sliced into strips. The strips are marked with signs, his word is notae, and scattered at random over a white cloth. A priest, for a public matter, or the head of the household, for a private one, prays, looks up, and lifts three strips one at a time, reading them according to the marks cut on them beforehand.
That is the whole of it, and it is genuinely evidence of Germanic lot-casting.
Why it is not evidence about runes
The chronology alone is decisive:
- Tacitus wrote around 98. He had never been to Germania and was working from earlier accounts and informants.
- The earliest securely dated runic inscriptions are from the second century at the earliest, most of the well-known early finds from the third and later.
He describes marks. He does not call them runes, does not describe their forms, does not say how many there were, and does not say the same set of marks was used twice. His notae could be runes, tally-marks, ownership marks, or anything else cut into wood.
Nothing in the passage indicates a fixed twenty-four-sign system with individual meanings. Three strips are drawn and read; there is no suggestion that a strip means anything on its own.
The rest of the evidence
There is no medieval Germanic or Norse text describing divination by drawing individual runes and reading their meanings. Runic inscriptions are overwhelmingly ordinary: names, ownership, memorials, prayers, obscenities, trade notes. A small number are plausibly magical (charms, curses, the alu formula), but that is a different claim from a divinatory system.
Modern scholarship is consistent on this. R. I. Page in particular treated claims for widespread runic magic and divination as an inflation of very slight evidence.
Why Perthro
Because this rune is the one most often produced as the counter-argument. Its name is the most uncertain in the whole futhark (the Old English poem's peorth stanza describes something that brings play and laughter in the hall, which has been read as a dice-cup, a game board, a chess piece and several other things), and the lot-cup reading has become standard in modern practice partly because a divinatory system would like to have a rune about itself.
The lot-cup reading may be right. It is a conjecture about a word nobody can translate, and it is not independent evidence that the runes were cast.