Raise Reader Tension: The Unknown

 Introduce the Unknown and you will have the reader on edge -- an immediate increase in
reader tension. You can do this at any point. I think Middles are particularly well-suited for doing this since Beginings are for set-up, Endings are for wrap-ups, but Middles are for complications. And what is more intriguing and unsettling  to the reader than an "I know something you don't know"? Especially right when the reader is getting complacent.

English: Hampoil cave entrance from inner angle (Photo credit: Wikipedia)

        Foreshadowing in prose, allusions in dialogue, or unexplained events are just a few ways to raise reader tension. Some of this might be plotted into your first draft but if you have places that sag but are necesary to the story, you can add elements of the unknown to draw the reader back into the story.
        Look for ways you can rewrite the scene so the characters explore a new area (a cave, empty building, new sector of the city. A place neither the characteer nor the reader has ever been before.
        Look for places where you tell back-story or history directly and without conflict. Or brainstorm back-story or history that is not included in the story but you wish you could have included. Turn this into a secret to be kept from the reader (and maybe the character) that must be discovered through hints and clues given out by various characters and settings.
        Take a character who is important (but maybe not vital) to the story and rewrite your manuscript so the reader never actually meets this character.
        Take your time when introducing a new character or setting. The reader doesn't need to know everything at once. In fact, the reader doesn't need to know everything at all just so long as you know. Show the action and take your time with the explanations. (Some explanations can wait longer than others.)
Introduce uncertainty, mystery, indecision -- the unknown -- to increase reader tension. Raise reader tension to help tighten the sagging, dragging passages of your manuscript.

Raise Reader Tension: Main Characters

         How can you increase reader tension? I mentioned that it isn't the character that has to feel the tension but the reader. One way to achieve this is through tweaks to your main characters. Remember that surprise is key to reader tension.

English: A thermite reaction using Ferric Oxide. (Photo credit: Wikipedia)

        One reason readers become complacent is that over time, they learn to predict character reactions. This is especially true in the middle -- after character has been established. By the middle, readers think they know everything there is to know about the character. If you allow this, there is risk that the reader will get bored.
Use their assumptions against them while remaining true to the character you have created.
        Give your character an unexpected reaction. Unexpected to the reader, that is. You will have to justify the reaction and the readers will see that there is more to the characters than they thought, maybe an unmet need, controversial belief, previously unrevealed back-story.

NOTE: this works best if you set up reader expectations before challenging those beliefs. Find several similar situations in your manuscript that evoke the same reaction. Then insert or alter a situation that is almost identical except that it includes a personal trigger that will cause the character to react differently. The reader will be surprised, confused, intrigued. The different reaction will put the reader on edge until the change of behavior is explained (in a way that stays true to character). Done right, you can also deepen character with this technique.

        Another way to use your main character to raise reader tension is to exploit his/her character arc. A character becomes predictable when turning points are delayed for too long, lack surprise twists, or have steps that do not offer enough change in character outlook/motive/behavior.
        These techniques should help you to keep your reader guessing and engaged with your main characters. Keep the reader unsure, keep the surprises coming, and you will be well on your way to raising reader tension.

Raise Reader Tension: Surprise

Tightrope Walker (Photo credit: the other Martin Taylor)

        Does your story drag when you reread it, despite a well-conceived plot? You may be having trouble with dramatic tension. A feeling of tension in the reader is vital to building suspense because it keeps the reader from feeling complacent.
        Reader complacency is the enemy to tension. A reader can still feel complacent -- and bored --  even when faced with the fastest, most action-packed plot.
        How can this be?
         The complacent reader knows what is going to happen. So even when the character is surprised, the reader is not. Predictability is the enemy to dramatic tension.
It is not necessary for the character to feel the tension, so long as the reader feels it.
        After all, the character isn't the one reading the book, turning the pages, making the decision whether or not to put the book down or stay up through the night. Tension in the reader overlaps with -- but is not identical to -- tension in the viewpoint character.
You can fight complacency with uncertainty. Not uncertainty in the character (though that can help) but uncertainty in the reader.
        Surprise the reader.