A methodological approach to identifying and quantifying video game difficulty factors

• Simulate gameplay between Pac-Man and ghosts using a variety of parameter values.
• Examine changes to game parameters and the impact on performance variables.
• Use a full-factorial analysis to identify factor effects and interaction levels.
• Summarize factors influence on the performance results and player’s strategy.
• Summarize benefits and limitations of the methodology to evaluate game difficulty.

Video games which are unable to identify and adjust the level of difficulty to the player’s ability have no mechanism to engage a player who is beginning to become bored or overly frustrated with their gaming experience. Players who are overly bored or frustrated by a game might completely abandon the game; as most players purchase games on the recommendations of other players, this can damage the commercial side of the video game (Bateman and Boon, 2006). Our research formalizes and evaluates a methodology for identifying and quantifying the effects of different game factors on a player’s performance. To evaluate our methodology, we have designed an experimental testbed based on the classic video game Pac-Man. The evaluation of player performance is subdivided into response variables based on collecting items, the overall score, and the ability to remain alive. In the testbed, the behavior of Pac-Man and the ghosts is simulated, and every parameter and algorithm within the testbed is capable of being adjusted. Our experiment simulates game sessions for Pac-Man and the ghosts, observing the impact of adjusting the different game factors on the player’s performance. The impact of a game factor and its interaction with other factors is evaluated using a full factorial analysis. The results of our analysis identify factors with varying degrees of impact on the player’s performance. In doing so, these results identify a small sets of game factors which have a prominent impact on nearly all players, in addition to a unique sets of factors which impact only specific player types.