How does teleportation work, exactly? That is, you are in one place, and then another; presumably, the air rushes in to fill the space after you are gone; but what happens to the stuff in the space you now enter?
Two possibilities. One, you somehow mingle with what you teleport into; the basis of both versions of The Fly, and of the nightmare scenario where you end up immediately dead after teleporting into a wall.
The other, which I prefer, is that you displace whatever you are teleporting into. Still leads to a sad and lonely death if you teleport into solid matter, but much more forgiving otherwise.
Of course, nothing says fantasy has to be consistent. Indeed, I'd think our intuitive approach to magical
Summoning sickness, anyone?
Displacement, likewise, has some interesting side effects if applied consistently. For example, any wizard's district or magical academy where teleporting is practiced constantly would probably have an abundance of the hallmarks of slightly off teleports: footprints in the floor where a teleport went slightly too low, or in some cases craters where a wizard had to be dug out of solid rock.
One of the better dead ends in a dungeon might be one where, using detect magic, somebody dug their way to the entombed corpse of a way-off wizard to rob him for his enchanted loot. All that's left is the indentation of his body, maybe a skeleton, and a cursed item for the unwary ....
Call it pedantry if you like - but it's the good kind of pedantry, where working out the details of a consistent world leads not to "this can't happen" or "this is more boring" but "wow, really, that happens?"
Finally, for some reason, fantasy teleportation doesn't seem to arouse the same worries about scrambling matter that sci-fi* teleportation does, at least if game rules are anything to go on. Maybe it's because we have an implicit model of magic as working off some idea of Platonic forms - a kind of object-oriented programming, if you will. Thus, the danger in a spell that changes the "location" attribute of "you" is not that you will be changed, but that you will end up where you don't want to be. By contrast, sci-fi teleportation works in a molecular physics of reality where it's much more clear that you will have to be disassembled and reassembled, monad by monad, giving rise to all sorts of philosophical dilemmas and wacky mishaps.
* Is the last person who viscerally hates this term finally dead?
Dungeon Magazine #136
4 hours ago