I began writing seriously with screenplays, and learned about using index cards to outline a story from my writing partner. Screenwriters have been using them for years, but I use them whenever I am writing a story that is too long or complex for the outline to easily fit on a page. They’re also particularly useful in that stage of writing (or rather planning to write) when you have lots of ideas, but you’re not quite sure how they all fit together.

While I like the tactile quality of the physical cards, as well as being able to lay them out on a big table or pin them on a cork board for reference, there are other options too. Well known writing software like Scrivener and Final Draft both allow you to create “virtual” index cards, and there is even an app that does nothing but let you write and organize with virtual index cards – “Index Card – Corkboard Writing.”

But how do you actually do it?

There are likely as many ways to use index cards as there are writers who use them, but rather than give you a “system” that may or may not fit for you, I’m going to describe how and why they are so useful.

A good story flows well from plot point to plot point, without “dragging” or “sagging” in between. While a novelist typically has a bit more license, in a screenplay that is limited by the acceptable run-time of a film, plot points happen with near Prussian precision. Taking this same approach when outlining a novel never hurts, in my opinion, even if when writing it you allow yourself to go down some interesting rabbit holes. Index cards are a useful method to help you create a well-balanced story, whose structure maintains tension and interest throughout.

In the Three Act Structure, the Second Act is as long as the First and Third Acts combined. I actually prefer to think of it all as four Acts (included 2a and 2b) all of equal length, but you get the picture. To achieve this structure, I decide on a total number of chapters (typically 20 or 24, though yours will vary based on the total word count goal and the size of your typical chapters) and divide these between the Acts. If you are wondering how to write or structure a chapter, check out this article.

In a 20 chapter story, I then have 5 cards/chapters in the First Act, the same in the Third, and 10 in the Second. At an average of 4000 words per chapter, this gives you a typical 80,000 word novel. I begin by jotting down the key plot points on the bottom of the index cards in the right positions in the layout. You can see what this looks like in the diagram below.

(This same method works when writing a short story, but in this case each card represents a scene rather than a chapter, or when writing a film, where each represents a sequence.)

This gives me a framework to start thinking about my story. I can then start to brain storm major events and jot them down on an index card. If I think of minor ones, I can start to add them as well, but at this point I write with a thick marker to remind myself not to get sucked into the details – I’m still thinking high level. As I get ideas, I may not yet know where they fit in the story, and that’s OK. The index cards let me rearrange the story quickly and easily, to try different things. Sometimes what I think will be the climax ends up where I start the story, and that’s OK.

Using this method, I have a 30,000 foot view of my story and can see how much material I have for each part. I can adjust the material as needed to give the story the right flow, and experiment with using different occurrences as my major or minor turning points. At this stage, everything is fluid and open to change.

As I start to solidify my story outline with the index cards, I start writing more details for each of the chapters on them (sometimes flowing over to the back as well). If I have a sub-plot that I want to weave through the whole story, this is a good time to do that because I can jot down a sentence or two in each chapter where I want it to appear. This lets me sometimes weave a handful of ideas through the whole story without detracting from the overall structure or flow.

When I am certain that I have the structure right, I go through and number the cards (and therefore the chapters) and collect them together into a pile that sits on my desk as I write. Each card guides me through writing a chapter, and if I want to look backwards or ahead, I can see where various things fit into the overall structure. I try to be disciplined about updating the cards with additional details that come to me as I write, so that when I am done the cards are an even better representation of the novel as a whole, to help me with editing (which invariably has a stage where I revisit structure to make sure that it works as well as I thought it would when I planned it).

There is a lot of material on the web that gives a detailed “system” for using index cards or other methods to outline a story, but I think that you have to try different things to see what works for you. I’m always a little suspect of those “killer” story worksheets or methods for writing that seem to prey on writers who aren’t sure where to start. There has been little new discovered about story telling since Aristotle, and everything you need to know can be found in your local library – through reading. Only practice will tell you what really works for you.