The degree to which magic and similar implements are readily available in a game affects how that game is played.
I'm just tossing that out there, believing it to be a fact that holds true for a majority of games and a majority of players/groups. Why exactly? Well, I suppose it's worthwhile to take a more careful look at this idea;
Ostensibly, we, as gamers, players, DMs, nerds, are liable to cathegorise settings and game systems accoring to how "fantasy" or "sci-fi" they are. There's that litany of well-known, handful terms, like "high fantasy", "low fantasy", "cyberpunk", "sci-fi", "weird fiction", and so forth, and so on. Even when we're not particularly thinking about it, we differentiate settings based on some degree of separation from our "normality", as in, this present day, the now, our perfectly ordinary life.
"High fantasy", the setting that on a first glance most readily abandons common conceptions and plunges the reader/player into a world of dragons, wizards, gods, monsters and magic is probably the most representative of the role-playing repertoire. Sure, D&D is what this is all about, a party of adventurers who wave their swords, wands, hammers, pythons, chalk and 60 ft of silk rope in the face of danger. D&D, in all of its incarnations, is a game that wants to be beaten. You need to roll higher than some arbitrary number, you want to take something's hitpoints (all of them), you want a shiny new sword with some number in front of it, the higher the better. Magic in D&D serves as an endless pool of enhancements and character growth (the mechanical kind). Spells, enchantments, rituals, they're there to give the characters outs from hot situations, to give them an edge in combat, to complement their character sheets. Alright, magic also serves as plot hooks, but it's not like you're awed by an ancient necromantic boneyard that's also a gate to the nether realms. That's as thrilling and mind-blowing to a D&D player as crayons are to a kid. Sure, they look great at first, amazing even, but after you've eaten your fifth stick of "Ocean Blue", they're just another way to doodle on the wall.
But then, if magic is essentially only there to be a tool, it's not awe-inspiring, it's... well, tool-inspiring, obviously. Forget magic for a moment, or rather, substitute the word "magic" for whatever else would fit in a different setting. "Super-science"? In a superhero campaign, again, it serves as power-ups or repetitive plot hooks. "Advanced technology"? A sci-fi game in which a rag-tag group of mercenaries stocks up on plasma rifles and nanobots to storm a compound, that's quite kin to adventurers and dungeons, no?
Point is, if something is widely and readily available, it ceases to be "fantastical". Last I checked, "mundane" meant something along the lines of "common, banal, ordinary". Soooooo, if every second shop in the city sells +1 longswords, are they fantastical or mundane?
Maybe at some point, the 80's or some other prehistorical period like that, it was concievable for a nerd kid with alarmingly oversized glasses to feel the "fantastic" when immersed with a world where wizards shot lightning left and right, and elven maidens danced in elite night-taverns just around the corner... But let's face it, we've become the kind of nerd young adults with alarmingly oversized glasses that yearn for something more. I can't say for sure what that "more" is, since I, as I believe the majority of my generation, am a confused, overstimulated creature, bombarded by information from all sides, and with the attention span of a goldfish swimming in a vat of crack. Yet, I know that it would be an insult to the cynical nature of our times to accept high fantasy as fantastical (which isn't to say it can't be fantastically fun to play).
I'd like to actually come to a conclusion here, but since there's still low fantasy and fairy tale fantasy and then some more to go over, I'll stop here for now. In the next segment, we should take a look and see what possibly could make a game fantastical.