This thesis explores how rule modification in multiplayer board games can affect the occurrence of kingmaking while still maintaining core functionality of the game. Kingmaking describes situations where a player with no chance of winning affects which other player wins. Through formal analysis, this thesis provides insight into how kingmaking is facilitated through design patterns and proposes rule changes that can help mitigate instances of kingmaking. The findings of this thesis are that there is no one solution that fits all games, and that a targeted rule modification is required on a game-by-game basis to mitigate kingmaking. The method allows game designers to strengthen fair gameplay, although its application needs to be adapted for each particular game.