Designing Games with Game Maker - YoYo Games

peferably only for small pieces of code. For longer pieces you are strongly advised to use
scripts which are described in part 2 of the documentation.
Comment
Use this action to add a line of comment to the action list. The line is shown in italic font.
Adding comments helps you remember what your events are doing. The action does not do
anything. But realize that it still is an action. So when you place it after a conditional action it
is the action that is executed if the condition is true (even though it does not do anything).
Set Variable
There are many built-in variables in the game. With this action you can change these. Also
you can create your own variables and assign values to them. You specify the name of the
variable and the new value. When you check the Relative box, the value is added to the
current value of the variable. Please note that this can only be done if the variable already has
a value assigned to it! See below for more information about variables.
Test Variable
With this action you can check what the value of a particular variable is. If the value of the
variable is equal to the number provided, the question returns true. Otherwise it returns false.
You can also indicate that the check should be whether the value is smaller than the given
value or larger than the given value. See below for more information about variables. Actually,
you can use this action also to compare two expressions.
Draw Variable
With this action you can draw the value of a variable at a particular position on the screen.
Note that this can only be used in the draw event of an object.
Score actions
In most games the player will have a certain score. Also many games give the player a
number of lives. Finally, often the player has a certain health. The following actions make it
easy to deal with the score, lives, and health of the player.
Set Score
Game Maker has a built-in score mechanism. The score is normally displayed in the window
caption. You can use this action to change the score. You simply provide the new value for the