Why compare mathematical studies with visual novels about pigeons, such as Hatoful Boyfriend (Mediatonic, 2014)? Because, surprisingly, they have something in common: game theory.

Game theory is the mathematical study of decision-making, outlined by Morganstern and Von Neumann; game theory specifically looks at how the player plans their course, what information is available at every step of the game, and how they put together a strategy (Morganstern, O. and Von Neumann, J., 1944). A genre of games leans heavily on this structure: visual novels.

Dialog tree.png
Example dialog tree. Who *is* Mr Bowler?!

Visual novels are text-based adventure games, regularly asking the players to choose between dialogue options to go forward with the knowledge that different choices will yield different results, and potentially change the outcome of the game. These different choices can be mapped into a dialog tree, which can also be considered a decision tree as each choice is meaningful for player progression. As Salen and Zimmerman note, interactive stories with hypertext structures make for smaller decision trees than more complex games, but are still a common way to flow-chart the player experience (Salen, K. and Zimmerman, E., 2004, pp.232-233).


Personally? Play video games.

Visual novels can add further complexity by adding player stats that can be changed via certain choices, as seen in Long Live the Queen (Hanako Games, 2012). In this game, actions result in mood changes, which can in turn affect how the protagonist reacts to events and character interactions. This link between decisions and outcomes is a key element of game theory, as stated by Davis (Davis, M., 1970, p.3), showing that once again visual novels make use of game theory to build the player experience.


However, it is worth noting that visual novels’ heavy reliance on game theory also has a pitfall, as it allows players to map out the exact path to victory leading to what Salen and Zimmerman call “degenerate strategies ” (Salen, K. and Zimmerman,J. 2004, p. 246), e.g. the exact path to victory. As they point out, this can diminish uncertainty and meaningful play…. but you do get your pigeon boyfriend at the end!


Davis, M. (1970) Game Theory: A Nontechnical Introduction. Mineola: Dover Publication.

Hanako Games (2012) Long Live the Queen. Hanako Games.

Morganstern, O. and Von Neumann, J. (1944) Theory of Games and Economic Behaviour. Princeton: Princeton University Press.

Mediatonic (2014) Hatoful Boyfriend. Devolver Digital.

Salen, K. and Zimmerman, E. (2004) Rules of Play: Game Design Fundamentals. Cambridge: The MIT Press.


Hatoful Boyfriend (2014). Available at: https://www.theguardian.com/technology/2014/sep/12/hatoful-boyfriend-review-love-pigeons-japanese-dating-sim (Accessed 13 November 2017)

Long Live the Queen (2014). Available at: https://www.kotaku.com.au/2014/07/keeping-a-princess-alive-is-harder-than-it-looks/ (Accessed 13 November 2017)

Dialog Trees (2017). Available at: https://en.wikipedia.org/wiki/Dialog_tree (Accessed 13 November 2017)