(Example: In 4-2 of SMB1, if Mario is far enough on the right side of the screen, he can use the pipe to go to the warp room since the destination info of the vine is still valid. If Mario is far on the right side of the screen, the entry point variable will be out of date, so a new entry point will lead to the target of the previous one.Once the screen scrolls far enough for the next target label to be loaded from the level data, all entry points in the current screen will lead to that destination instead. The reason lies in how the game is designed: There is just one global variable in the game RAM that determines where pipes or vines in the current screen lead. Theory: The game can have only one 'entry point' (a pipe or vine) per screen. The Wrong Warp glitch occurs when a pipe takes you somewhere other than its intended destination.
