No, I'm not talking vampire-killing tools here. Stakes are what give your story a sense of urgency or purpose for whatever it is your character has to do. Stakes are what makes your reader keep reading. Stakes are what happen if your character DOESN'T overcome the obstacles in his or her way, or get what he or she wants.
Stakes usually inhabit each scene and chapter as well as tie into the overall story. To get a sense of what I mean by stakes, let's look at some popular stories.
If Michael Corleone fails to take control of the family's position relative to the other families, his death will be certain and gruesome. In order to preserve his power and his life, he must win. The stakes are his family's power and lives.
The Wizard of Oz
If Dorothy doesn't kill the witch as directed by the wizard, then he won't help her get home and she'll remain in Oz forever. The stake is her returning home.
Star Wars (original)
If Luke doesn't blow up the Death Star, then the Empire will take over and crush everyone and the force. The stakes are millions of lives.
If the space marines don't blow up the aliens on the planet, then um....well it wont be good. No. For the space marines, the stakes are their lives, although they don't know that going in. For Sigourney Weaver's character, Ripley, the stakes are more complicated. They're putting to rest the bad memory of the aliens that killed her crew (back in the original movie, Alien).
Bella is bent on loving Edward, but Edward might kill her at any moment. The stake is her life. (And might I add, this stake is why the book is so popular. Anytime you're in love with your killer, it makes for a good story.)
Sometimes you don't want to give away the stakes because it will reveal a piece of the story that might want to be a twist. However, there should always be a sense of tension, a sense that the stakes won't be met.
Stakes are often, as evidenced by Twilight, also appropriately thought of as hooks (but not premises). If your stakes are good and high enough, then everyone will be leaping at the story.
Can you cite some good high stake stories in movies or books?
Can you cite what the stakes are for your characters in your own novel?