Mouse Double Click is a free extension that provides a simple to implement double-click detection function. There are two functions: mouse_doubleclick_init() creates an instance variable used to check for timing the two click events. Put this in the Create event for your instance. mouse_check_doubleclick() checks to see if the mouse button has been clicked, and if so whether there was an earlier click recorded within the time threshold specified in the function call. Put this in the step or mouse events of your instance. Can work with left or right mouse buttons. You can determine the delay that will trigger a double click detection. Since this was so simple to implement, and since I felt like GM:S ought to have the capability to detect double-clicks built into it already, this one is free Marketplace Asset Full Documentation Please review it if you give it a try!