Setting

The area a story (or a majority of it) takes place in. I didn't plan on it being quite so lengthy.

See, setting can effect the plot in not only elaborate ways, but in the most obvious ways.

EX: If your story features a princess of medieval times, chances are she will not own a car, phone, or any other technology, nor will she ever be seen wearing pants and a t-shirt, for this is not how a woman or girl would've dressed. You may be thinking right now, 'Well duh.' But exactly! Never, ever would it make sense for such modern items be used in medieval times, unless of course something about a time warp that transfers her to 21st century, and even then she's not where she's supposed to be.

Now, if the princess were a 'city princess', chances are that you have more equipment to work with. Of course, her 'knight in shining armor' is probably the school quarterback, and not a valiant, bold man riding upon his trusty steed. 

   

A MEDIEVAL PRINCESS                                                    A CITY PRINCESS

Not only does time refer to what items and indulgences are at use, they also make for the contents in the writing itself, and possibly whatever the plot's problem is. You don't want (and please do not take this to heart, it makes for an example and nothing else) ANYTHING racist in your story whatsoever, unless it takes part in around the 1960's or earlier, back when color of your skin was actually an issue. If set in 1960's, the reader understands the terms you use, and the reaction between others, now, if it was set 2010, you have complications with your story and reader as well. This also goes for if your story takes place in historic events such as the Pearl Harbor, The Holocaust, Bloody Sunday, Korean War, King Tut's death, Cleopatra's reign, The Soviet Union, and anything you could think of.