Developed a customizable encounter type feature for the ArchipelagoMW/Archipelago repository, enhancing gameplay in Pokemon Emerald by allowing players to tailor which encounter types are available. The work involved designing and implementing species eligibility logic and refactoring the existing encounter randomization flow to support new configuration options and future extensibility. Using Python and object-oriented programming, the developer integrated these changes seamlessly into the game’s codebase, focusing on algorithm design to ensure robust handling of player choices. This update improved replayability and player agency, laying a technical foundation for further enhancements to the encounter system within the broader game development context.