Why Is This So Hard? Insights from the State Space of a Simple Board Game

Abstract

Serious Games research has become an active research topic in the recent years. In order to design Serious Games with an appropriate degree of complexity such that the games are neither boring nor frustrating, it is necessary to have a good understanding of the factors that determine the difficulty of a game. The present work is based on the idea that a game’s difficulty is reflected in the structure of its underlying state space. Therefore, we propose metrics to capture the structure of a state space and examine if their values correlate with the difficulty of the game. However, we find that only one of the metrics, namely the length of the optimal solution, influences the difficulty of the game. In addition, by focusing on the part of the state space, which is actually explored by human players, we can identify properties that predict the game’s difficulty perceived by the players. We thus conclude that it is not the structure of the whole state space that determines the difficulty of a game, but the rather limited part that is explored by human players.