Monday 23 July 2012

Classifying and Rating Linearity

When most people are reviewing a gamebook, I find that they often comment on its linearity, and quite often gamebooks that are considered linear are given negative reviews. But so far I haven’t seen anyone really give an in depth analysis as to how linearity works and what the different levels are.
I myself enjoy a gamebook that is as non-linear as possible; I want my decisions to have impacts on the plot; if I wanted a linear plot, I would have read a regular book. So I have come up with a classification system to help define the different levels of linearity and non-linearity. Included are images of plot trees showing roughly how each classification of gamebook would look if it were mapped out. The circles with the numbers represent pages/sections, and the arrows show decisions and the direction of the arrow shows which direction they lead.

Linear gamebooks are essentially regular books that may have added in die rolls and combat, maybe giving you the option of one or two choices along the way that do not affect the plot whatsoever. One might also consider books that allow the reader the choice between two endings on the very last chapter to also be linear.
Examples: Of all the gamebooks I have played I have to say Quest for the Dragons Eye was by far the most linear. Honestly I think there were maybe three choices available to the player the whole way and each converged back to the main plot after only one page. At the beginning of the book there is a map of the dungeon. It’s essentially a straight line. Enough said.

Gamebooks that are Convergent are the kind that may give the player a variety of options and a small area to explore, before bottlenecking the different paths the player may have taken so as to force the player to follow a specific path in the end. This level of linearity isn’t really that bad seeing as it usually required to structure a gamebook with a good plot; it may not be a good thing to let the reader run too far away from their main mission.
Examples: Most gamebooks, such as Fighting Fantasy, Virtual Reality, Lonewolf and Spellcaster are structured this way. Take for example the beginning Citadel of Chaos; there are many routes you can take when crossing the courtyard, but no matter what you will always end up at the gate on the far side with the rhino man asking you for the password.

 A Divergent gamebook is one in which few, or none, of the plot strands you may choose to follow ever meet up with any of the other plot strands. If you are given the choices A and B, then few or none of the pages you can reach after reading A will be the same as any of the pages you can reach after reading B. This forces the book to contain many unique outcomes and ending all revolving roughly around the same plot. One thing about Divergent gamebooks is that internal consistency is never an issue; in one plot strand a character may be completely different than in another plot strand, this allows for a lot more replayability.
Examples: Choose Your Own Adventure, Give Yourself Goosebumps, Pretty Little Mistakes and most other gamebooks that only feature choices without other game mechanics are structured this way. A good example is the first gamebook I owned The Deadly Experiments of Dr. Eek, in which depending on the series of choices you make you might find that Dr. Eek is doing experiments on monkey, or on dogs, or that you’re in the wrong building and that it’s Dr. Ek you’ve encountered, not Dr. Eek.

Free Roaming
One of my favorite forms of gamebooks, but sadly one of the rarest is Free Roaming. In Free Roaming gamebooks the player is allowed to do what they please and is usually given a plethora option to choose from, as well as a number of locations they can explore at their leisure. This level of non-linearity really gives the reader the wonderful feeling of being able to explore the authors world and truly “living” in it. The only drawback is it can be difficult to add in plot to a book when the player is given such a large amount of freedom, however most of the great gamebook authors I know have managed to add good plot elements while keeping such a high degree non-linearity.
Examples: Fabled Lands, Tunnels and Trolls, Scorpion Swamp and À Vous De Jouer! Are examples Free Roaming adventures. Fabled Lands is one of the best known examples; in the six interconnected books you can go on quests that will take you across the lands, interfere with the politics of the regions, and fight monsters for treasure. Or you can simply buy yourself a nice home, stay as a guest at a castle and go sailing around the coast. Whatever you would want to do in a fantasy land, you can do in Fabled Lands.

This rating system is not perfect, especially because many books will be a somewhat blend of two of the levels. For example The Legion of Shadow can be considered Free Roaming because the player is given their choice of where to go on the map and what they do in the cities. However it can also be considered Linear or Convergent when the player goes on a quest because most of the choices quickly lead to the same plot of each quest. I would also say that Lonewolf is also slightly more on the Linear side of Convergent, while Virtual Reality is more on the Free Roaming side of Convergent.

Lastly the mathematician in me has a few comments to make and ideas to share: it might be possible to create a formula to give gamebooks a quantitative rating of non-linearity, as opposed to the qualitative rating system I have given above. This could be done my counting the number of paths it is possible to take through a gamebook from start to each of the endings (this would probably have to be done by a computer due to the number of ways some gamebooks allow you to mix and match different subquests) Then use this number to classify how linear the book is; it would give a index of how paths there are through the book. We could call it a Gamebook Path Index (GPI). A Free Roaming gamebook would be instantly recognizable because it would a GPI of infinity. A regular non-interactive book would have a GPI of 1. I may try to use this method to classify the short adventures I have written so far seeing as they are short enough that applying this method of classification should be manageable. Note that GPI would be affected greatly by the length of the gamebook, and for some gamebooks may not give an accurate idea of how linear the gamebook is: I am working on a formula based upon GPI to be more accurate.

I would love to hear what YOU have to say about this classification system, what YOU would do to change it and/or improve on it. Do YOU prefer gamebooks that are Linear, Convergent, Divergent, or Free Roaming? So please leave comments!


  1. I enjoy all these kinds of gamebooks on their own merits (although I don't have much experience of any 'divergent' ones). Linearity does detract from the sense of being in control of your own destiny; however I find the storylines in such books are usually tighter and make more sense. As a player I find that I take satisfaction in finishing such a book because I know I've explored most of what it has to offer and I haven't missed out on anything. Of course the other side of the coin is the lessened replay value.

    At the other end of the spectrum, free roaming books are great for that 'sandbox' feel where you can go anywhere and do anything - however the storyline usually suffers as a result. In this sense these books are more games than books. I love Fabled Lands but there is something that seems a bit futile about wandering around doing random quests with no real end goal. These books are also more difficult to design in terms of continuity (didn't I already kill this bandit?), although SJ did a pretty good job with Scorpion Swamp.

    Convergency seems like a good compromise, and I guess this is why I love FF so much. Enough to start my own playthrough blog anyway :)

    Interesting post, keep it up!

    1. Thank you for the feedback! I completely agree about each of the different categories having their own merits, especially depending on what the author was trying to do: indeed the Convergent gamebooks are better for plot, while Free Roaming are better for game-play. Though I thought that Fabled Lands did a decent job in incorporating plots all considered: for example the "righteous king" plot in The War-Torn Kingdom.
      P.S. if you'd like to try out Divergent gamebooks, any from the series' I mentioned above will do: Give yourself Goosebumps, CYOA, and Pretty Little Mistakes.

  2. Love the post - generates lots of thought.

    I would love to create a divergent gamebook where all of the paths actually lead to some kind of successful ending which is pretty tough if the quest is 'slay the wizard' as the wizard can only be in one place. Maybe if you go somewhere at different times? Or if you had to recover one of several items?

    There's one thing about divergent books (and gamebooks in general) that I've thought about but haven't yet covered and that's how situations could be different based on the player's choices. For example, you could have a dungeon and say that there's an emerald in room A. However, if player does action X, they will find room A to be empty. It raises all kinds of questions, but that's something that is not really used in gamebooks.

    It is also hard to do a plot in free roaming books as you have said above. Fabled Lands had small plots that involved finding out about them in place A, going to place B, doing X and then returning to place A again. I suppose a free roaming book with a plot would involve every place having something to do with the plot and you manage to move on to some 'secret' location when you have put all of the pieces together.

    What I'm aiming to do at the moment is to add more divergency to my convergent books.

    1. I agree that 'slay the wizard' type plots might be difficult to work into a Divergent gamebook, but other plots such as 'escape the X' work well with that type of linearity. Gamebooks that deal with large periods of a character's life are usually written in this style. For example Life's Lottery, and Pretty Little Mistakes are quite Divergent.

      I find that Give Yourself Goosebumps occasionally uses the "if player does A, there will be an emerald, but if player does B, the room will be empty". But it hasn't been used for any more complex systems, nor is it usually discussed at depth in the gamebook community.

      It is true that plot is usually more difficult to incorporate; usually the plots are small and don't go into a lot of depth. Reflection on it, I would say there are two ways authors add plot to their Free Roaming gamebooks:
      A) Do like in Fabled Lands and allow the player to freely decide to go on small quests with plots.
      B) Have an encompassing plot like in Scorpion Swamp or Escape the Kingdom of Frome. In Scorpion Swamp you have a quest to complete for your master, so once that's done you win. And in Escape the Kingdom of Frome, you're wandering around until you find you way out.

      I look forwards to seeing your new Divergent gamebooks! And I love your Free Roaming ones, especially Khazan City Chaos.

  3. Great post! I'm a big fan of free-roaming books, but as Stuart said, it's very difficult to properly plot them. Fabled Lands did have an over-arching plot, but it really went on in the background and I never felt particularly involved in it too much.

    I think have keywords in divergent structures could definitely allow for an organically flowing book, where certain things happen depending on player actions (see Bloodbones and Fabled Lands).

    1. Glad you liked the post :) I would have to say Free Roaming is also my favorite type; I've been meaning to buy your Thornguard, as soon as I set up an account with Lulu. Looks great; you should write more like that!
      I agree with you on keywords, especially in the Free Roaming and Convergent gamebooks. Keywords help Free Roaming types, (such as Fabled Lands) allow you to have an impact on the world you are exploring. And in convergent types (I would say Bloodbones is Convergent, albeit it does have Free Roaming elements to it) allow your past action to have effect and allow the gamebook to diverge once more even after a bottle necking convergent point (or a "funnel" as the analysis on would say)

  4. Have you seen this analysis of the old Choose Your Own Adventure books?

    1. I just finished reading the analysis. Fantastic stuff; I especially liked how the analysis referred to frequency diagrams showing how likely the reader is to pass by certain pages. Also interesting that the analysis noted that CYOA books became less divergent and more linear throughout the 80s. Bizarre.
      An excellent analysis. Thank you for pointing it out to me! :)

  5. This website of gamebook flow diagrams is very good at showing the different types:

    Deathtrap Dungeon (FF6) is very linear whereas Scorpion Swamp (FF8) is free roaming with its interlinked groups of paragraphs.

    Midnight Rogue (FF29) is convergent until about half way through before it gets linear and the CYOA books are very divergent with short trees.