Another element carried over from “Resident Evil 1.5” was the use of two protagonists. However, rather than have their stories occur in complete isolation like in the original, Kamiya and Sugimura worked together to come up with a new mechanic called the “zapping system.” Leon and Claire explore the same locations and solve many of the same or similar puzzles, but because their stories occur simultaneously, players must finish both scenarios to witness the entire story and earn the true ending. Leon and Claire cross paths from time to time, so there are instances when the actions in one scenario directly affect what happens in the other. The most notable would be deciding whether it should be Leon or Claire who acquires a specific weapon; players must weigh the pros and cons of the decision, as it could make things easier in the first scenario but more difficult in the second, and vice versa.