Differences

A couple of differences in the book to movie transfer, in the movie the orcs blow up the wall at Helm's Deep through the culvert. In the book, the sneak in through the culvert and there are no explosives. Another thing is at Minis Tirith, Denethor sits back and doesn't want help, and nobody comes until the attack, but in the book, a couple of princess come to help him, and he orders the beacons lit, Pippin doesn't do it.