Resident Evil 2’s gameplay system that changes events between campaigns is called the Zapping System. It links the scenarios of Leon Kennedy and Claire Redfield so that actions in one campaign can influence the other.
The original 1998 game presents first scenarios and second scenarios. After completing one character’s route, players can begin the other character’s corresponding scenario, encountering altered item locations, puzzles, enemies, and story details.
The system was designed to make the two campaigns feel connected rather than simply repeating the same adventure with a different character. It also encouraged players to finish both routes to see the broader Raccoon City story.
The term is associated particularly with the original Resident Evil 2. The 2019 remake retained separate character campaigns but changed their structure and did not reproduce the original system in exactly the same way.