Laggy, jumpy cursor in-game (only in-game) MAC. Ever since I deleted LoL and re-installed it; my cursor is very laggy and jumpy when I am in-game. This problem only occurs in LoL and already starts in the loading screen. I have no issues with other games so I know that the mouse is not the issue, the same happens if I move around with the trackpad. y2tAc.