When player skill levels differ widely in a competitive First-Person Shooter (FPS) game, enjoyment suffers: weaker players become frustrated and stronger players become less engaged. Player balancing techniques attempt to assist the weaker player and make games more competitive, but these techniques have limitations for deployment when skill levels vary substantially. In this thesis, we developed new player balancing schemes to deal with a range of FPS skill difference, and tested these techniques in a series of five studies using a commercial-quality FPS game developed with the UDK engine. Our results showed that our balancing techniques (Combo and Delay) are extremely effective at balancing, even for players with large skill differences. These techniques also led to higher enjoyment of the game by players of all skill levels. Our studies are the first to show that player balancing can work well in realistic FPS games, providing developers with a way to increase the audience for this popular genre. In addition, our results demonstrate the idea that successful balancing is as much about the way the technique is applied as it is about the specific manipulation.

Game designers spend a great deal of time developing balanced game experiences. However, differences in player ability, hardware capacity (e.g. network connections) or real-world elements (as in mixed-reality games), make it difficult to balance games for different players in different conditions. In this research, adaptive time-variant minigames have been introduced as a method of addressing the challenges in time balancing as a part of balancing players of games. These minigames were parameterized to allow both a guaranteed minimum play time (the minimum time to complete a minigames to address the fixed temporal constraints) and dynamic adaptability (the ability of adapting the game during the game play to address temporal variations caused by individual differences). Three time adaptation algorithms have been introduced in this research and the interaction between adaptive algorithm, game mechanic, and game difficulty were analyzed in controlled experiments. The studies showed that there are significant effects and interactions for all three factors, confirming the initial hypothesis that these processes were important and linked to each other. Furthermore, the studies revealed that finer temporal granularity leads to less-perceptible adaptation and smaller deviations in game completion times. The results also provided evidence that adaptation mechanisms allow accurate prediction of play time. The designed minigames were valuable in helping to balance temporal asymmetries in a real mixed-reality game. It was also found that these adaptation algorithms did not interrupt the overall play experience.

Game balance has been a challenge for game developers since the time games have become more complex. There have been a handful of proposals for game balancing processes outside the manual labor-intensive play testing methods, which most game developers often are forced to use simply due to the lack of better methods. Simple solutions, like restrictive game play, are limited because of their inability to provide insight on interdependencies among the mechanisms in the game. Complex techniques framed around the potential of AI algorithms are limited by computational budgets or cognition inability to assess human actions. In order to find a middle ground we investigate Game Theory and Mechanism Design concepts. Both have proven to be effective tools to analyse strategic situations among interacting participants, or in this case `players'. We test the feasibility of using these techniques in an Real Time Strategy (RTS) game domain to understand game balance. MicroRTS, a small and simple execution of an RTS game is employed as our model. The results provide promising insight on the effectiveness of the method in detecting imbalances and further inspection to find the cause. An additional benefit out of this technique, besides detecting for game imbalances, the approach can be leveraged to create imbalances. This is useful when the designer or player desires to do so.