In the rush of plot or riveting drama, it can be easy to forget that your hero and heroine haven’t eaten for twelve hours or slept for three days. Sometimes this might happen, but the causes and consequences better be believable. Including these elements, or at least the acknowledgement of them, can go a long way toward giving a story believability.
Another one that’s easy to forget is the physical strain of activity or wounds. If your hero is in a fight and takes a few hits, he’s going to have a hard time climbing a mountain. If he’s in that fight and escapes unscathed, he’s likely to at least feel tired. Any intensive activity expends notable amounts of energy. Keep these things in mind.
One of the best ways to protect against forgetting the basic needs of any hero is to keep track of the time in your story. Keep a log of the day and hour, or a rough approximate. You don’t have to tell the reader every meal your character eats, but if he’s flown a star fighter for the past sixteen hours and you don’t give a nod to the fact that he’s tired and hungry, you rob your story of verisimilitude.
Also, human, aliens or fantasy creatures, if you have them, have other needs as well. Each species of Ionian or dragon will need something a little different. But don’t forget non biological needs such as social interaction and emotional fulfillment. A true loner that doesn’t crave these is extremely rare.
The biggest advantage of maintaining an awareness of your characters’ needs, physical, social, emotional, or mental is that you can play with them to add tension and conflict to a story. In fact, depriving a character of a need, whether fully or in part, often becomes the basis for a lot of plots, and the universal understanding and deep levels of motivation that this can uncover can make a story that much more riveting.
What stories can you think of that hinge on an unfulfilled need? How did it work? In contract, can you think of any books that didn’t incorporate this principle? How did it impact the story?