When I started this I was thinking more in terms of world flavour to be honest.
That was what I thought.
Sure, fireballs are little missiles. Although, I find the idea of intercepting one to be more of an Internet thing. I mean, would you allow someone to intercept an arrow? What's the difference? To me that's just a theoretical that will not see play very much if at all.
Agreed.
World flavour has changed its purpose over the years.
Back when the game came out the world flavour was to explain what the heck the creatures were.
Hmm. When the game came out there was really very little flavour text for monsters.
From Chainmail, pp 29-30:
HOBBITS: These little chaps have small place in the wargame, but you may want them for the recreation of certain battles. Remember that they are able to blend into the background and so make excelent scouts. . . .
SPRITES (and Pixies): These are also small creatures who have the power to become invisible . . .
DWARVES (and Gnomes): Because their natural habitat is deep under the ground, these stout folk opeate equally well day or night. . . . Gobins and Kobolds are their natural (and most hated) enemies. . . .
GOBLINS (and Kobolds): Goblins and Kobolds see wel in dimness or dark, but they do not like bright light. . . .
ELVES (and Fairies): Armed with deadly bows and magical swords, Elves (and Fairies) are dangerous opponents considering their size and build. . . .
ORCS: Besies reacting to light in the same manner as Goblins do (after all, Orcs are nothing more than over-grown Goblins), Orcs are quarrelsome and factious. According to the best authority, there are at least five kinds (tribes or perhaps clans) of them. These are: 1) Orcs of the (Red) Eye, 2) Orcs of Mordor, 3) Orcs of the Mountains, 4) Orcs of the White Hand, and 5) Isengarders.
I've elided the wargames rules, but no flavour text.
From Book 2: Monsters & Treasure,pp 7-8, 16:
GOBLINS: These small monsters are described in CHAINMAIL. . . .
KOBOLDS: Treat these monsters as if they were Goblins . . .
ORCS: The number of different tribes of Orcs can be as varies as desired. Once decided upon, simply generate a random number whenever Orcs are encountered, the number generated telling which tribe they belong to, keeping in mind inter-tribal hostiity. . . .
Note that if Orcs are encountered in an area which is part of a regular campaign map their location and tribal affiliation should be recorded, and other Orcs located in the same genera area will be of the same tribe. . . .
Orcs do not like full daylight, reacting as do Goblins. They attack Orcs of different tribe on sight unless they are under command of a stronger monster and can score better than 50% on an obedience check . . .
HOBGOBLINS: These monsters are large and fearless Goblins . . .
PIXIES: Air sprites as described in CHAINMAIL . . .
GNOMES: Slightly smaller than Dwarves, and with longer beards, these creatures usually inhabit the hills and lowland burrows as opposed to the mountainous homes which Dwarves choose. They are more reclusive than their cousins, but in all other respects resemble Dwarves.
DWARVES: Because of their relatively small size [various combat consequences] . . . They are otherwise as outlined in CHAINMAIL.
ELVES: Elves are of two general sorts, those who make their homes in woodlands and those who seek the remote meadowlands. . . . Elves have the ability of moving silently and are nearly invisible in their gray-green cloaks.
[Etc]
I think assumptions about play changed - from the idea that a group (led by the GM) would make of this stuff what they wanted to, based on their familiarity with existing fantasy, myth and legend, to the idea that part of what was fun about the game was playing in an already-authored canonical setting. You can see the beginning of that change in AD&D, but it really emerges in the mid-80s (look at the different nature of the flavour text in Unearthed Arcana and Oriental Adventures, for instance) and then grows over time.