Why is the Solar so powerful compared to other beings from the planes?
It's a tradition, since the introduction of that creature in Dragon
Magazine issue #64, 1e edition AD&D, and subsequently Monster Manual
II. (A lot of stuff rolls over from edition to edition).
A Solar is the most powerful of spirits, usually directly serving a greater deity of Good alignment, typically as his or her marshal, steward, or like office. On rare occasions, a solar will be found attending a lesser deity. There are at least 24 solars. They can go to any plane, but do so only in service to their deity. (MM 2 p 111 & Dragon #64 page 11).
Feature Creep. As supplements came out for the original edition of AD&D, the new stuff tended to be "cooler / better" than the old stuff" -- this is true in more recent editions' splat books and supplements. Demons and devils were "old stuff" from the 1977 monster manual, and the Solars (most powerful of spirits and opposites to demons and devils) arrived in 1982 (Dragon #64) and 1983 (Monster Manual II).
(Dragon 64, p. 10). Last issue this column introduced itself with Devas, the proverbial right hand of the forces of Good. Following the same vein, here are two even stronger powers who faithfully serve the deities of the Upper Outer Planes, Planetars and Solars. Tremble, ye hordes of Darkness, at the mere mention of these shining examples of the Hosts of Justice and Freedom, the Great Servants of Good! -- ©1982 E. Gary Gygax. All rights reserved. Dragon #64 August 1982. --
As with the various mythologies, deities, and pantheons folded into the game, adapting a Judeo-Christian inspired angel-type took something already known and fit it to the game. (Note the Christian god is NOT in the game). These powerful good beings serve any of the in-game Good deities already in place.
- The original artwork took archetypical angelic form from of angels in Eurocentric art and culture: long hair, wings, long white robe. (True in Dragon #64 article and MM 2, and for Deva in Dragon #63 p 6-7. Angelic wings, good alignment, but short hair?)
- The right hand servant of deity, supernatural being one notch down from a deity. That is what Archangels are in Christian mythology. Re-skinning that to Solar gets you the most powerful spirit (And look how long that model has lasted: see archangels in the Diablo series of video games ...)
- Archangels of yore cast into Hell the devil (once an archangel) and all of his subordinates -- they have to be seriously badass to do that. Making Solars "the most powerful spirit" fits the model they were taken from.
- Angels were proposed, but finally not included in published books, even though an article on p. 32-33 in on Dragon #17 explicitly notes Judeo-Christian roots of D&D.1
The parallels to the Choirs of Angels from Christian belief (mythology if seen from outside the religion) is a re-skinning to arrive at "similar but different."
- There are very few Archangels, just as there are "24 known Solars."
- Lesser angels serve Archangels, while Planetars and Devas are subordinate to Solars.
- Wings, robes, flying. While it's not a direct cut and paste, it is recognizable, and different enough to both deal with cultural taboos(see below) and add a balancing set of supernatural beings missing from the planes of existence. (PHB 1e p. 121).
Cutting and Pasting Angels(Christian) as could be done for some devils and demons could not done for two reasons.
- The first is the taboos of the time. (see below)
- The second is the game had already promoted a multi-theistic paradigm since the publication of Gods, Demigods and Heroes (OD&D supplement 4, 1976) and Deities and Demigods (1e supplement). Demons didn't have to be re-skinned. A game-friendly re-skin of the Angel and Archangel solved both problems.
- One can recall that originally Balor (demon) was called a Balrog and Type VI (Eldritch Wizardry) when first introduced. That had to be changed (re-skinned?) due to external pressure: Tolkien's estate. With angel, the re-skin came before publishing.
(Slight digression) An example of the kinds of cultural taboos that Gygax and friends dealt with in contemporary culture surrounding them: in films in the 50's and 60's you almost never saw anyone portray the character of Jesus Christ and have the actor show his face on screen. (Ben Hur is one example.) This taboo was eventually broken, but shows such as Jesus Christ Super Star and The Last Temptation of Christ earned criticism from Christian groups in a variety of denominations ... including the "face of Jesus" complaint. (Lost in a long list of complaints). I remember reading about this firestorm as a teen, when it was a contemporary flailing - culture clash. Gygax was aware of the cultural sea they were swimming in, and, he also didn't want to mix his religion and his business. (1) D&D received its share of vitriol from Christian sources.
D&D was influenced by a variety of literature, stories, myths and legends, and added from many sources as it grew and developed. Influences on the authors included basic Western Christianity, civilization, and cultural touch points. D&D was originally built on a Dark Ages / Medieval European chassis
I'm very fond of the Medieval period, the Dark Ages in particular. We started playing in the period because I had found appropriate miniatures. I started devising rules where what the plastic figure was wearing was what he had. If he had a shield and no armor, then he just has a shield. Shields and half-armor = half-armor rules; full-armor figure = full armor rules. I did rules for weapons as well. -- Gary Gygax--
Christendom, as a cultural model, was the state of being of Europe around the time of the Crusades. (Note, the Castle and Crusade Society was the wargaming club that fought medieval miniatures table top battles.(See intro to Men and Magic p. 3)).
Core cultural references from Christendom embedded in D&D from it origin include:
- Clerics' strongholds (when achieving Patriarch level) levied tithes (Magic users and Lords levied taxes)
- Paladins influenced by Oiger the Dane, Sir Galahad, Sir Lancelot (the last of whom healed a slain opponent at a joust by laying on of hands)
- Raise the Dead spell brings people back to life (cf. Lazarus raised from the dead, and legends of the Apostles doing same)
- Clerics and Paladins influenced by the Knights Hospitlar / Knights Templar of the Crusader era
Adding a supernatural archetype(angels and archangels), albeit re-skinned from standard Christian symbols and mythology, is (a) NO surprise and (b)fits the game's theme. It also served to both balance to the demons and devils already present, and flesh out the higher planes of existence. (See Appendix IV to the original PHB, on p. 121). The occupants of evil planes were well accounted for, the good aligned planes ... not so much, even though it was proposed in Dragon #17 in 1978(see footnote 1).
Finally, Gary Gygax was a life long Christian(1). Him fitting angels into a game full of the supernatural is consistent with the core themes woven into the game from before its first draft. Re-skinning them to deal with taboos is related to his internal conflict between his game and any overt Christian influence on it. Gary Gygax spoke about later in life: (Gencon Indy, 2007, discussion with Christian gamers).
(1) At GenCon Indy 2007, Gary sat on a panel discussion, hosted by the Christian Gamers’ Guild and treating the topic “Christianity and Gaming.”
Gygax described himself as a Christian, but for much of his life had been reluctant to discuss his beliefs, citing fears that he would hurt the reputation of Christianity because of his connection to the moral panic that some people associated with D&D as a reason for not having been more vocal about his faith.
"I was reticent to say the fact, you know, that I was a Christian, mainly because I was afraid that I would give Christianity a bad name because I did D&D. So I did, I kept my mouth shut. But I just decided no, I’m not going to do that any more."
1 (Dragon #17, p. 32-33; August, 1978; Stephen Dorneman)
In Eldritch Wizardry, Gygax and Blume have given nefarious Dungeon Masters a plethora of immensely evil, incredibly powerful supernatural beings, the demons. A worthwhile and logical addition to Dungeons and Dragons, and just the thing for trashing that arrogant twelfth-level’s castle. From Gods, Demi-Gods and Heroes a DM can draw for purposes
of divine intervention that practically omnipotent being particularly suited to his or her universe. But something is still lacking in this panoply of other-worldly creatures. There is a need for beings powerful, yet not omnipotent, who would be in the service of the good gods. And so, in keeping with the Judeo-Christian tradition of D&D, propose the creation of a new class of supernatural beings, Angels.
Angels, unlike demons, should only appear on Earth with a particular mission, a manifestation of a god’s will. They may appear in response to prayer (with a base 1% per cleric’s level chance of response), if summoned by various holy artifacts, as guards for certain holy shrines or relics, or at the whim of the gods.(/snip the rest of the article)
This answer to the original question came before Mordenkainen's Tome of Foes was published. @illustro's answer covers that gound in this answer.