Even though fiction is, by definition, a story that describes imaginary events, places, and people, and, anecdotally, the writer is only limited by his imagination, the story still has to be believable.
This means that the rules within the story (no matter the genre) have to make sense.
If we're going to believe that every year a group of tributes competes against each other in a match to the death, this has to sound reasonable based on what we know about the story world, as this type of competition set in modern Western civilization would seem implausible.
This means that an author has a lot of work to do.
A reader begins to care about a character when they feel the events could happen to them, and the more you deviate from the rules of the time and place with which they are most familiar, the sharper your world-building skills need to be.
If you world-build correctly, you probably won't include half of what you know about your time and place and its history within your novel, but it's still important that you know it.
Be Brilliant!
~Katie~