This year has been a wild ride for lovers of science fiction and fantasy. Some hugely expensive, massively hyped projects have failed, but also some new mega-hits have been born. Hollywood is struggling with sagging movie ticket sales and TV ratings, and book publishers are facing a rapidly changing world. It's a tough time — and you have to learn fast to survive.

Most of all, it's been a year of harsh lessons. Here are the biggest things that 2011 taught the entertainment industry.

1) Dark fairy tales rule
When Grimm and Once Upon a Time went head to head, we might have predicted that one of them would triumph while the other one fizzled. But no — apparently, Once Upon is a hit, and Grimm is doing respectably in a tough Friday night slot. And there are approximately 500 Snow White movies in production now, including two with Julia Roberts and Charlize Theron, respectively, starring as the evil Queen. Plus a Hansel and Gretel movie is coming next year, too. And some of the most buzzed-about young-adult novels have had a fairy tale theme too, including Cinder, a cyborg Cinderella story by Marrissa Meyer and Melanie Dickerson's Beauty and the Beast retelling. (Although see below — a couple fairytale movies bombed badly in 2011 by trying to appeal to the Twilight audience.)

2) We love clever dystopian scenarios — but not if they're too preachy
Dystopias continued to be popular, including a number of new young-adult novels. And post-apocalyptic worlds continue to be a favorite theme, especially zombie apocalypses. But people seem to lose interest in dystopias when they get too contrived and/or preachy. Witness the failure, this year, of the long-awaited Torchwood: Miracle Day and Andrew Niccol's return to movies with In Time. Both Miracle Day and In Time were about worlds where you could live forever, and they both sought to dramatize social inequality through some pretty heavy-duty lecturing. Everybody seemed to decide they wanted their dystopias a bit more escapist and, well, fluffy.

3) Science fiction is a hard sell on TV these days
This may have been a great year for fantasy on TV, but sadly, it was a pretty bad one for science fiction. In addition to the aforementioned failure of Torchwood U.S.A., this year saw the cancellations of V, The Event, Eureka, and a few other shows. Stargate Universe also ran out its final episodes this year. And two other shows that featured universe-hopping and time portals, Fringe and Terra Nova, appeared severely endangered. Any show with science fictional trappings faced an uphill struggle this year, especially if it wore its science fiction trappings proudly. The year's one big science fiction success was Falling Skies, which was the most popular new basic cable show of 2011.

4) Genre mash-ups shouldn't get too high concept.
When you think about the summer's biggest movie flops — Green Lantern and Cowboys & Aliens — the thing that jumps out about both is that they're mashing up existing genres. The mash-up aspect of Cowboys is right there in the title, but meanwhile Green Lantern wanted really badly to be a combination of "superhero origin story" and "Star Wars-style space opera." With dashes of Training Day and a wacky "man-child grows up" comedy. People have to believe that you can make two or more distinct genres work together, without obvious seams, or getting too contrived.

5) There's only one Twilight and one Harry Potter
This year's Twilight and Harry Potter movies broke box office records. Their imitators? Uh, not so much. There was a string of wannabes that fell flat or got middling box office, from Beastly to I Am Number Four to Fright Night to Red Riding Hood. (Add 2010's Percy Jackson to the list too.) Meanwhile, The CW's Vampire Diaries has kept doing well arguably because it's shaken the "Twilight for television" label. People love their Twilight and Potter, but they don't seem to want an endless raft of knock-offs, at least not on the screen.

6) The trend of literary authors writing genre novels became a flood
In 2010, there were a number of literary authors doing genre books, who generated some excitement by bringing a literary eye to vampires (Justin Cronin's The Passage) or monster movies (Rick Moody's Four Fingers of Death). But in 2011, I honestly couldn't name all of the books with science fiction or fantasy themes which got published as "mainstream literature" — because there were so many of them coming out. Pretty much every month brought a few new ones this year, with the not-terribly-surprising consequence that some of them got lost in the shuffle. For every literary-genre foray that generated excitement, like Colson Whitehead's Zone One or Lev Grossman's The Magician King, there were a few which seemed to sink without much trace. Even among mainstream reviewers. Has the trend peaked? Maybe we'll find out in 2012.

7) We love the underdog.
The underdog who goes up against impossible odds continues to be a favorite theme, whether it's in robot boxing (Real Steel), alien invasions (Falling Skies and Battle: Los Angeles) or court intrigue (Game of Thrones. Even if you hadn't read the book, you knew Ned Stark was out of his depth the moment he arrived in King's Landing.) Nobody wanted to identify with The Man this year, everybody wanted to be up against The Man. As predictable as these underdog stories are, there's something comforting about them in a world when the "little guy" (or gal) is generally getting crushed underfoot. Science fiction fans, in particular, love lost causes — it's one reason we get so passionate about TV shows that are on the brink of cancellation. This year, I kept getting the feeling that "underdog" fantasies were the new "chosen savior" fantasies.

8) People are leery of futurism, but even more so of retro-futurism
This is only tangentially related to science fiction or fantasy — but it's hard not to notice how badly nostalgia failed this year, especially nostalgia for the futurism of a bygone era. Shows like Pan Am and The Playboy Club which tried to give us a Mad Men-style look at social change in the 1960s — without Mad Men's sophistication — went down in flames. The Charlie's Angels show tried to trade on nostalgia too, and nobody was much interested.

9) A movie deal is becoming a must for debut novelists
It's been true for quite some time that having a movie deal in place is a huge help to building buzz for an author — but this year, it felt like a necessity for maybe the first time. The year's biggest debut fiction authors all had movies in the pipeline before the books even hit bookshelves. Including Daniel Wilson's Robopocalypse, Ernest Cline's Ready Player One, Erin Morgenstern's The Night Circus and Isaac Marion's Warm Bodies. If a book has already been anointed by Hollywood as the Next Big Thing, then it's a sure bet that book readers will be at least curious. Even if the movie never gets made, being optioned is a seal of approval.