I just finished a supposedly fantasy story in a well-known pro magazine (I won’t name names for fear this actually gets read) and was not impressed. 

The story was only so-so, but the worst of it was that the fantasy element was nothing less than someone’s delusions.  The tale wound along, dancing around this concept the crazy guy had, and headed toward resolution in which the man capitalized on his fantasy, then at the last minute tacked on a bit where the guy’s fantasy came true.  The crazy guy wasn’t even in the story anymore, as it was told from the pov of a supporting character.

The Submission guidelines over at Analog say this:

“Basically, we publish science fiction stories. That is, stories in which some aspect of future science or technology is so integral to the plot that, if that aspect were removed, the story would collapse. Try to picture Mary Shelley’s Frankenstein without the science and you’ll see what I mean. No story!”

And it seems to me that fantasy should work the same.  The fantasy should be integral to the story, insomuch that if you remove the fantasy element the story doesn’t work.  In the crazy guy story I just finished, the fantasy was just an irrelevent tag.