There's no violence like implied violence.
''All writing is deception, and what better way to sucker people into buying your book, than by promising the inclusion of an epic fantasy battle. So gather the armies, raise the banners, and prepare for war. Let's get the reader pumped up for that great battle. Raise the tension, build towards this massive confrontation, and then fade to black before having the other characters remark what a close battle that was. Hah! Dodged that bullet. I'm sure no reader will feel cheated that the great battle the entire story has been building up to was just mentioned in passing between chapters."