About "dumb" luck

Pure luck, blind luck and dumb luck, are expressions used to refer to:

• complete luck; nothing but plain luck. I have no skill. I won by pure luck. (McGraw-Hill Dictionary) (Macmillandictionary.com)

• Curiously, as Ngram shows, the three expressions "pure luck, blind luck, dumb luck." have all been used from the same period, the middle of the 18th century.

1) The use of pure is quite intuitive and refers to something

• Complete; utter: pure folly. (AHD)

2) The use of blind refers to e the Roman goodness "Fortuna" (Lady Luck nowadays)

• Fortuna (Latin: Fortūna, equivalent to the Greek goddess Tyche) was the goddess of fortune and personification of luck in Roman religion. She might bring good luck or bad: she could be represented as veiled and blind, as in modern depictions of Justice, and came to represent life's capriciousness. (Wikipedia)

~ But what does 'dumb' refer to? How was it that this term came to be associated with luck?

Solution 1:

Dumb luck is a chance event that has no meaning behind it. It's one that's completely random.

Dumb did not originally mean foolish and ignorant. It first meant having no voice, and thence meaningless and senseless, and that latter aspect of meaninglessness and senselessness is the very sense in which it was first applied to luck or chance.

The foolish sense came afterwards, and although it is now the dominant one, it does not apply here. Rather, dumb luck is a fossilized example of the more ancient sense: it is not an example of the present-day sense of foolish.

This more ancient sense of dumb is the one given by OED sense 7a meaning senseless, which it classifies as now rare. Note the reference to dumb chance — which is the same as dumb luck — found in the third citation.

7a. Saying nothing to the understanding; inexpressive, meaningless; stupid, senseless. Now rare.

• 1531 Tindale Exp. 1 John (1537) 53 ― They wyl breake in to thy conscience, as the byshop of Rome doeth with his domme traditions.
• 1542–5 Brinklow Lament. lf. 18 b, ― A popishe Masse··is to the people a domme, yea a deade ceremonye.
• 1643 Sir T. Browne Relig. Med. i. §17 ― ’Twas not dumbe chance, that··contrived a miscarriage in the Letter.

The original meaning of dumb is the one that has no voice, carried by senses 1–6. Sense 7b is the later one meaning foolish and ignorant as applied to persons.

Solution 2:

"Dumb" meaning lacking in intelligence. Thus emphasizing that the outcome came about by means other than intelligent planning.

From The Illustrated American (Volume 3, 1890):

Does judgment enable a man to win at a horse-race, or does success require that higher and rarer quality, dumb luck?

From Puck (Volume 49, 1901) below a sketch of bowlers, one of whom has knocked down all the pins, the following exchange:

Huzza! That look like bowling!"
"Thou thinkest it skill, then, and not dumb luck?"
"Oh, well, dumb luck may look like bowling!"

(emphases mine)

Solution 3:

There's a possibility that dumb relates to ancient Germanic, in a sense pre-historic law as practiced at the Thing, where judgement was delivered. Thing is a loan from old Norse into English, so it's not apparent that it's cognate to doom.

dumb luck would then be destiny, as opposed to doom. It's not quite tough luck, although the semantics would match much better--the knowledge about the past traditions has nearly faided, so it should be difficult to decide one way or another.

It just fits that no voice in the figurative sense, as pertains to votes and the like, is a usual consequence of being sentenced. While dumm "stupid" and dumbatz "daumb-ass" (YMMV) exist as such in German, it should be of note that mute is generally stumm, closer to stammer and perhaps stump (Ger. Stummel "vestigal", stumpf "blunted, numb"). As much as s- prefix seems to alternate arbitrarily between English and German lemmas, and even across Indo-European languages (s-mobile), it should be really tuff to say what went wrong, where and when.