Here is the AD&D first edition version.
First, it depends on whether you are talking about the clerical or mage version. The clerical Darkness was actually the reverse of the Light spell. The PH makes no mention of how it affects infravision or ultravision... only the duration and area of effect.
Now the Mage spell, Darkness 15' radius, does state that "total, impenetrable darkness in the area of effect. Infravision and Ultravision are useless. Neither normal nor magical light will work unless a light or continual light spell is cast. In the former event, the darkness spell is negated"
Why was the spell nerfed? To provide more challenge to the players one must assume.
Now here's the original reference to Darkness. There was no Darkness spell in (basic) D&D. It was added in the Expert D&D expansion, and was referenced as a reversal of the Light spell. It was considered the same for both cleric and mage. It was described as a circle of darkness 30' in diameter that would block all light, but would allow infravision to work. A light spell cast on it would cancel it, and a failed save after casting it on someone's eyes would blind them.
The term definitely predates D&D - the term "twenty dollar gold piece" has been in use for the $20 Double Eagle and $10 Eagle coins of the late 19th century, and also the $5 gold coin, as well.
"Gold Piece" In Print
The term is used in the Lebanon Daily News, 1 Nov 1965, of Lebanon, Pennsylvania, bottom, in an advert for old coins under the left column of text (to the right of the comics)
Four gold pieces: One (1) $20.00 gold piece, two (2) $10.00 gold pieces and one (1) $2.50 gold piece.
This alone establishes the phrase "gold piece" for gold coins in routine use prior to D&D. But let us press a little further back... say, 1913? Here's a quote from the 5 August 1913 Cedar Rapids Evening Gazette, from Cedar Rapids, Iowa, page 4, top of the third column:
The five cent piece ls the day laborer of our coinage. It la the hardest working and most successful bit at money In use In these United States. The twenty dollar gold piece Is very popular and is madly sought after In the best society; the five dollar bill has millions of friends and the hard silver dollar can be found nestling In the pocket of almost every man. But none of these like the five cent piece.
We thus have established a pattern of use for gold coins of being called "gold pieces" in the press, spanning over 5 decades; clearly not a D&D origin; not even viably a wargaming origin, for 1913 is the year of the first printing of H. G. Wells' Little Wars, the first commercially released set of wargaming rules in book form.
Searching Project Gutenberg, several ebooks have it in use...
These without clear denomination prefixed:
- Pinocchio (1883, Tr. ??? )
Author: Carlo Collodi, 1826-1890
Translator: Carol Della Chiesa, 1887-
- The Younger Set (1907)
Author: Robert W. Chambers
- A Drama on the Seashore
Author: Honore de Balzac (1799-1850)
Translator: Katharine Prescott Wormeley (1830-1908)
- Tiger Cat (1938)
Author: David H. Keller
- Pâkia (1901)
Author: Louis Becke
And several with clear denomination in dollars:
Piece
Piece is, according to several dictionaries, a common term for coins in general, of whatever denomination is specified. The quote below is excerpted from the etymology online page:
piece
early 13c., "fixed amount, measure, portion," from O.Fr. piece (11c.), from V.L. *pettia, probably from Gaulish (cf. Welsh peth "thing," Breton pez "piece"), from O.Celt. base *pett-.
[...]
Piece of Eight is the old name for the Spanish dollar (c.1600) of the value of 8 reals.
Commentary
It's pretty clear that it's a generic term for a gold coin, and for several US gold coins as well. In the US, it seems to be predominantly the popular $5 coin of the late 19th and early 20th centuries, but can be used collectively for the $2.50, $5.00, $10.00 and $20.00 gold coins; The silver coins of similar values were $0.10, $0.25, $0.50, and $1.00. Note that, still to date, "2 bits" is $0.25... a reference to the not uncommon practice of breaking Pieces of Eight (Dollares, or Reals) into 8 "bits" of an eighth-dollare each... I suspect that this is the origin of the 20:1 Silver:Gold ratio in AD&D...
Best Answer
It's based on a toy.
And that's all most sources will give you, because they're drawing from an article (Ed Greenwood's "Ecology of the Rust Monster" in Dragon #88, later quoted by another article of the same name in issue #346) which is actually about the rust monster, and only passingly mentions the owlbear. In fact, the original quote is so vague it's hard to tell if they actually mean to say the owlbear shares the same origin as the rust monster (a plastic toy).
But Tony DiTerlizzi gives us photos of the actual toy which inspired this freaky creature, and so here it is, the original owlbear:
It comes from a pack of early 1970s cheap plastic toys depicting "prehistoric animals," most of them entirely made up. Look, you can see the bulette and the rust monster, too:
The origin of these toys is from Hong Kong, where they made these toys to resemble monsters from the 1960's famous UltraMan TV show. source