Built In Global Variables

GameMaker Studio 2 has a collection of "built in" global variables and the majority of them are very specific and will only be used on rare occasions - these are listed in the appropriate sections of the manual - but there is one important one that is used frequently and isn't listed elsewhere:

There are also three "helper" built in global variables to control certain general aspects of your game which you should be aware of:

IMPORTANT! These variables are only designed to support legacy projects from previous versions of GameMaker and should not be used in new projects as they may be deprecated in the future.