TL;DR: Your story has a better chance if it fits the aesthetics of the magazine. Your story has a better chance if it has a strong beginning. Your story has a worse-than-normal chance because it is fantasy. But people are fickle, so you never know. Your story has no chance if the ending sucks.
Andy: So, I'm going to pretend like I know what I'm talking about because I interned for a publication and have a vague idea of what goes through the minds of people reading through the slush piles.
I'll warn you straight up, unless it's a magazine that's specifically looking for genre fiction, fantasy stories (re: your story) probably won't get through slush unless it's absolutely, balls-to-the-wall, Mark-Twain-and-John-Steinbeck-had-a-kid-and-Kurt-Vonnegut-was-the-godfather brilliant. And even then...
At least at the Blue Mesa Review, genre fiction (not just fantasy--horror, romance, historical fiction, etc) was especially bad about it. Kind of for good reason, because all of it that we got (the stuff I read anyway) was tripe. In all honesty, had you mailed that off and I read it for the magazine I probably would have panned it. Not because it's bad (comparatively, it would have easily been the best piece of fantasy fiction in the pile... oh, man, you should have seen some the couple of fanfics we got), but because it's not mind-fellatingly awesome enough to shirk the stigma surrounding genre fiction.
Second thing: Regardless, that's with all stories, though. "Literary" fiction was regarded much more highly, but even then? Magazines, even small unknowns like BMR have a pretty high volume of material coming in all the time. People usually put in about an hour at a time to reading submissions, and by the end of it it all starts to blend together and it's hard to give ANY story a fair shot. It's pretty shitty that one's story can get panned and rejected because of things like this, but it happens.
Not that you shouldn't submit your work. I personally feel your story needs a couple of revisions before it will get picked up (and when I'm around IRC later this week I'm totally down to bounce ideas around), but you really shouldn't let that stop you. Revise it, yes, but send it out now regardless, then send out the revision later. Worst case, you have a bunch of rejection slips and getting rejected next time is easier. Best case, the story strikes the right chord with the right person/group, and blam, you're published. There's certainly going to be different standards at different magazines, but above all getting published is a pretty damn fickle thing.
Last bit of advice: If you want a good shot at breaking the slush reader malaise you need a damn fine first two pages and a good follow through the next few. One of the editors told me she only read the first two pages unless it really hooked her, and only finished reading if it didn't immediately drop off in the next couple. This is important. More important than that, though, is the ending. I can't count how many times I read a story, completely prepared to recommend it for a discussion meeting and then to argue for it to be published, and then the ending sucked--or worse, it was simply mediocre. So keep that in mind--strong beginning, stronger end. It matters.
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Hoo. Man. So I didn't realize this class was ending this week until a couple nights ago. Busy busy busy. Final paper done, and I finally heard back from some teachers who are willing to let me sit in on their classes. Huzzah! Now I just have the final project and test to do. Not so bad, except that the project is due Saturday evening, and I have no days off until then. It's doable, but ugh.