Action events can be used to program the behaviour of your project after a certain event has occurred. For example, you can use action events to define how your project should react once a certain button or key has been pressed. Hollywood Designer supports a large number of inbuilt action events.
If there is no action event that does what you need, you can use the the Run code action event to call into Hollywood directly and access the complete Hollywood command set from your Designer project.
You can also run action events outside of any event handler's scope by using the action object which is a special object that has no visual representation but just contains a list of action events to run whenever the script flow reaches its position.