Often in a story a character has to learn some pieces of information in order for the plot to keep moving. Sometimes it’s a few lines, sometimes it’s a whole lot of information that threatens to bring the fast action adventure pace of an exciting story to a screeching halt. That is the dreaded info dump. But there are a number of ways around it.
There are different kinds of information you may have to give your audience. Science and history, whether real or fictional, are the most problematic. Even if your hero has to sit through a lecture, you don’t want to lecture your audience. One way to do it is to break up the information. Give a little piece of information in one scene, then some more later on. This also works with the principal of telling the audience only what they need to know at the time. This can also work as comedic frustration for your character. “Now you tell me this?” “You couldn’t have told me this sooner?”
Or you can get it out all at once at the beginning before it can slow down your plot. Think of James Bond movies. They start with a big action scene and get you hooked. Then 007 goes into Q’s office and is basically told everything he and the audience will need to know for the rest of the movie.
If it is a larger concept, there is the rule of threes. That is, you hit a major point three times. Look at the original Star Wars. We are introduced to the Force when Obi Wan explains it to Luke as the “binding energy of the universe”. We next see how it can be used when Luke practices using his lightsaber against that floating, laser-shooting ball. So by the time Luke has to use the Force to destroy the Death Star, we have enough of an understanding of it. The same principle was used in Back to the Future. Marty McFly is given a flyer about the thirtieth anniversary of the clock tower being hit by lightening. Then, when Marty is back in 1955, that flyer provides the only way he is going to have enough electricity to get back to his own time. Then we see Marty and Doc Brown use that information to get Marty back to the future.
Another way is to focus on how the information effects the character that finds out about it. “Luke, I am your father.” Now the focus is on the character even though it’s the information that’s important. You can also disguise the information. When Marty is given that flyer, it’s unimportant to him. It seems like a throwaway line. Or the audience can see something the character doesn’t. Then there is the tension of when is the character going to find out?
Or if you need to know how something works, have it break. One thing Gene Roddenberry said about the technology of Star Trek is that Kirk would never sit down and explain how a phaser works just as Joe Friday wouldn’t explain how his revolver works. Both men would just use it. But if it breaks, now they have a reason to explain to someone what they need to find to fix it and why.
One last thought about science and history is something steampunk author Cherie Priest once said. “You will always have too much and too little.” You will always have readers or viewers who will be fascinated with the information and want more, or they will say they would have understood the plot better if they were given more. Others will say it was too much unnecessary information and it just slowed everything down. You can’t please everyone. So just give out the information you feel is necessary.