By the time you've written the first few paragraphs of your story or novel, you've already signed perhaps the most important contract in a writer's life: your contract with your reader.  This term refers to the expectations that the reader builds about the narrative that is about to unfold, and how you as a writer fulfill or confound those expectations.

I don't advocate fulfilling every expectation, nor defying them all, but rather understanding the expectations you are likely creating, and making deliberate choices about how to manage them to your ultimate conclusion. You cannot control the mind of the reader, or what s/he brings to the work, however, you can consider how the choices you make about the work will influence that mind.  It's said that the beginning of your book sells that book, and the ending sells your next one: you delivered a satisfying read, and they can't wait to see what you're offering the next time.

Packaging

The initial part of the contract may be out of your hands.  Your reader receives the work in a pre-packaged form that is already building expectations.  The cover of the book or magazine, where and how the reader acquires it, and whether they recognize the name of the author, editor or publishing house are all factors in the mind of the reader.  Alas, while these aspects of the work form the reader's first impressions, they are rarely under the author's control.

Opening Scene

The key aspect of the contract that you're in charge of is the opening scene.  Editors often make the decision to reject on the first page or within the first chapter.  Part of the hook is the contract that you're offering. Where does this book fit in the genre?  What is the tone of the book?  What type of content will be found here?  What possibilities does this world allow or deny?  If you have not yet written the work, choose a starting scene that showcases the excitement of the people and environment you are bringing to life.  We often think we should start carefully and draw people in—but beware of overestimating the patience of the reader.

Establishing Genre

Genre expectations are a big factor.  Fantasy readers like to enter into an alternate world with new possibilities, and they will immediately be looking for the signs that tell them what this world will be like.  Your job as a writer is to present that picture as clearly as possible.  What sub-genre does the story occupy and how is that signaled to the reader?  If they are forced to guess, or if they suddenly find their guess contradicted, they get annoyed. Imagine you start to read what feels like a sword-and-sorcery adventure, then the lead characters are falling in love and the remainder of the plot deals with their romantic conflicts, rather than the adventure plot you were starting to enjoy.  How would you feel as a reader?  Don't be that writer.  If you want to blend romance with your adventure, introduce that idea as early as possible.  Show the character's need for a life partner as well as the need to defeat the villain.  Weave these subplots together in the narrative.  Give both the inner and outer conflicts sufficient weight.

The First Page

Consider that first page.  What cues can you give the reader to place the work as a romantic adventure?  A turn of phrase that calls romance to mind, a thought or remark that shows the character's mindset?  A moment shared between the characters that builds interest in their relationship?

First Peek at Your Fantasy World

World-building expectations are the next broad category.  This is where you create the image of your world for the reader, and begin to show what kinds of things can happen.  Don't think of this as a limitation on you, but rather as determining the natural principles underlying your creation, and where they intersect with your scenes.  Is there magic here?  Will there be fantasy creatures in the jungle?  If you are writing in a contemporary setting, how will the reader know that it is not simply mainstream?  A brief reference to the supernatural elements that will later be significant could be all you need.  You can use metaphor or imagery to suggest the mystical even in a work that requires the protagonist to be surprised by these things later.  Keep in mind that, thanks to the packaging—even if it's just your cover letter or the guidelines of the 'zine you submit to—your reader is not likely to be surprised.

Narrative Tone

Tone of the narrative is a more subtle contract.  Is the work satirical? Humorous?  Serious?  Epic?  Are your language choices supporting how you would like the reader to feel?

Shock Level

The shock-level of your content is an especially tricky concern.  While readers who care about your characters will follow them into many dark places, just as many readers may be offended if your peaceful and light-hearted opening leads to graphic sex or strong interpersonal violence.  What level of potentially offensive material will appear in the course of the book?  How will that material be presented to the reader—as direct point of view, hearsay or off-stage action?  Clearly, you need to preserve your ability to incorporate shocking material in a way that will appropriately surprise the reader, but this need should be balanced with the desire of the reader to keep turning pages.

The mystery and romance genres are fortunate to have sub-genre categories that serve as rating systems for the reader: the "cozy" mystery will not contain shocking material, while the "spicy" romance is expected to raise the heat level over the "sweet" version.  We, alas, don't have such distinctions.  Dark fantasy is very popular, but even then the levels of sex and violence may vary widely.

Be aware of the potentially offensive material in your book and how quickly this material will be revealed.  The dark fantasy series I’m currently shopping starts with a grim medieval childbirth scene.  It's not for the faint of heart, but it sets the reader's expectations appropriately for the events that will follow. I  would rather a potential reader decide to put the book down early than that they blog (and tweet and Amazon review) about their sense of betrayal later on.

It may help to think of your opening as a sort of "trailer" for the book to follow.  Think about the movie trailers you've seen that got you excited but failed to capture the film.  A great trailer might bring in the crowds—but if word gets out that the film isn't anything like it, the crowds dwindle quickly.

Short Stories

The contract for short stories is more specific.  They are often read in one sitting—strengthening the association between the expectations and their fulfillment—and their length implies that every word counts.  You cannot have a throwaway dialog to establish character if the topic under discussion is not relevant to the story.  Remember that old saw about the gun over the mantelpiece needing to be fired by act three?  Your short story is like that stage set.  Everything you bring onto it must be there for a reason—at the very least, the reader will assume that it is.

Do You Deliver?

Take another look at your opening, or better yet, give the first few pages to a trusted reader and ask him or her to describe what she'd expect to find if she keeps reading.  Is that the experience you deliver?  If not, are you confident of your choices—are you delivering something that's still in keeping with what you've promised—or is this first contract with your reader also likely to be your last?