For instance, let us say that the world is in danger in your trilogy, and you want to build the world and make us care about it before you tell us it's in danger. (Wise. I have put down fantasy trilogies for trying to tell me the world is in danger in the first chapter, because it means the world is built of cardboard.) Or the reader really needs to know about the pre-existing relationships before you reveal that one lucky ducky among the characters gets to carry the magic item. Or you really need to know what a loser the character was before he -- oh, inherited a noble title and an estate.
(Spending large chunks of your first chapter -- or page -- or paragraph -- in the past perfect may be a clue here.)
The trick is -- well, I don't think it has an agreed-on name. I've heard it called bridging conflict -- I've called it that right here in this very journal, just a few entries ago -- and I've heard it called a set-up subplot. (Anyone know any other names?)
But what to do is ensure that the main character has another conflict that gets him where he needs to be for the main conflict to kick in, and foreshadows it, and (best of all) gracefully segues into it.
The students at the wizards' university are studying like crazy to get a shot at the best graduation challenge -- which means their relative standing is even more important than their absolute knowledge.
The heroine is squabbling with relatives over her inheritance before she finds out what it includes.
The hero is journeying along the deserted road because he is fleeing a feud.
The Lord of the Rings doesn't do this. It's one of its weaknesses. After Bilbo's party -- fun but not exactly propelling the plot -- Frodo sits around for years before his life is thrown off balance. Characters in a story ought to passionately want something enough to do stuff about it at all times.