I like the way National Treasure handled back story. This has implications for me, as a writer of fiction, for the movie is really an illustrated novel. In fact, it probably was a novel before it was a movie.
The prologue of young Ben Gates learning about the treasure and how his family became involved with it is essential to understanding the story. It did not have be a prologue, obviously, but I think the prologue works better, rather than working this in as remembrances by Ben during the story. In just a couple of minutes, the stage is set for the rest of the story, including the estangement of Ben and his dad. Very well done, IMHO.
The movie then cuts to the scene in the Arctic, many years later, with Ben and companions on the quest for the Charlotte. No information is given as to how Ben learned: that Charlotte was a ship, not a person; which Charlotte among other ships; learning its itinerary; and figuring out its final resting place. All this is for the viewer to imagine. Even during the balance of the movie, almost no hints are given about the missing years. The only ones I can think of are when the FBI folks are digging into his background. So we don’t know what Ben did to get to the Arctic.
But, we don’t really need to know. An intelligent viewer can figure out in broad concepts what he did. He spent his entire life after the attic scene looking for the treasure. He obtained education in fields that helped his search. He dug around archives for a person named Charlotte who was connected with Charles Carroll or other signers of the Declaration of Independence. He figured out that Charlotte in the clue was a ship, not a woman. Etc. Etc. He traces the ship to an Artic voyage of no return, and somehow figures out where the ship ended its fateful last voyage. All of this comes to the viewer in an instant, in the cut from the attic to the Arctic. Well done.
Also well done is the lack of back story about the relationships: Gates with Ian, Gates with Riley, and others. The story is not harmed by lack of knowledge about these, even with only limited back story supplied during the movie (poker buddies, windowless cubicle). Sufficient for the viewer’s enjoyment is that these people did meet, form relationships, and start working together. The specifics are not important.
May my handling of back story in the fiction I write be as good as in this movie.