What is an infodump?
An infodump is a chunk of text where the author attempts to explain/justify their plot developments through long passages of rationalisation. These will often contain overly complex scientific or supernatural phenomena which strain the boundaries of plausability. They should not happen.
Why shouldn't it happen?
There are a couple of reasons why infodumps should not exist. The first is that if you have a plausible and well crafted plot line, there should be no need for infodumps. If you are adding infodumps it may be a sign that you are trying to push the plot in a direction it shouldn't go. The next is that there are really simple things you can do to avoid the need for an infodump, as explained below.
What can I do about it?
- Show don't tell. This is the simplest and most straightforward way of avoiding an infodump. If there's something you want to explain about an event, write a flashback or a diary extract or something.
- Your characters should not be know-it-alls. What this means is that if there is a concept you want to explain, have you characters discover said concept instead of having it handed to them on a platter by an all-knowing being or having the characters explain it to the readers. Not only will your readers understand the concept better than with an infodump, but your characters get to feel smug about having found something out. Double win!
- Let the story go where it will. If there's a concept earlier in the book which doesn't fit with what you're writing now, either bin it or write something which fits with what you already have. That way you don't need any infodumps to fix your convoluted plotline, and you aren't sending your readers to sleep.
This is so annoying it needs a section all on its own. There is a certain kind of infodump which trumps all others. For the sake of categorisation, I'm calling it the series infodump. It's that block of text you get at the beginning (and sometimes throughout) the continuation of a series of books, explaining the events which happened previously. It's often written as such a short synopsis of what happened in previous novels as to be no use whatsoever to the person reading.
How to fix it? Screw the people who haven't read the last book, and I mean that seriously. If they didn't put the time or effort in to do so, they cannot expect you to sum it all up in a few paragraphs. Think of it as tuning in half way through a conversation. You may miss some things, but you'll pick up on stuff fairly quickly. By all means refer to events in previous novels, but do not go out of your way to explain them. If they want to know what happened, they can just read the book they skipped.
Now I hope you take at least some of that on board. There is absolutely no reason for an infodump, and I hope never to see one again. Unfortunately that probably won't be the case. Even the best writers end up with infodumps. Take Vampire Academy, for example. The constant restatement of events (the series infodump) turns an otherwise thoroughly enjoyable series into a cringe-fest worthy of a sit-com. And that, my friends, is nothing if not a damn shame.