Most people know that juries often decide who wins and loses at trial. So, in cases where a jury trial is involved, what exactly is the judge's role?
The judge's first role is to make sure all the parties and witnesses follow proper court room procedure. Although this doesn't sound particularly exciting, procedure is of vital importance to the legal system. It was designed to ensure that everyone who comes to court gets a fair trial.
As far as TV shows and movies go, you can see procedure and rulings come into play when a judge responds after one of the lawyers makes an objection. In such circumstances, the judge is usually ruling on the part of procedure that governs evidence. The jury is only allowed to see or hear certain evidence so that they are not unfairly prejudiced toward (or against) one party. Although many questions about evidence are settled before the start of trial in pre-trial motions, sometimes these decisions have to be made on the fly while court is in session.
Most trials have two arguments going on at the same time. The first is the argument over the facts of the case: who did what, where, and when? The jury usually decides these questions, although in some types of cases the judge can act as fact finder. The second argument is about the law. Each party's lawyer will study the laws written by the legislature and past cases to determine the exact status of the law. Then, the lawyers argue with each other about why the law favors their respective clients. Sometimes, when both parties mostly agree on the facts, this happens during summary judgment. When the facts are in dispute, the judge will provide the jury with instructions about the law so that the jury can make an educated decision about the case.
For more information on the court and what happens in a law suit, see FindLaw's section on Litigation.
Contact a qualified attorney.