Set

Sets a local or global variable to a specified value. This value can be a number or an expression.

Arithmetic Operators:

Operator	Description
+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulus (do integer division and return remainder)

Notes:

When using only numbers in the calculation, you need to use at least one decimal point to tell the game that you want to use floating point division, without a decimal point the remainder is truncated at the end of the division:

float a
set a to 9/5    ; will set "a" to 1.000
set a to 9.0/5  ; will set "a" to 1.800

When your variable is an integer and you want the result to be rounded you need to use a decimal point in the division and add 0.5:

short a
set a to 9/5          ; will set "a" to 1
set a to 9/5   + 0.5  ; will set "a" to 1
set a to 9.0/5        ; will set "a" to 1

set a to 9.0/5 + 0.5  ; will set "a" to 2
set a to 7.0/5 + 0.5  ; will set "a" to 1

Examples:

set a to 2
set b to a*a
set c to (b - a)*b - a
set d to ((3* -b+a) - c)/ -2
message "a=%.0f, b=%.0f, c=%.0f, d=%.0f" a b c d     ; ("a=2, b=4, c=6, d=8")

set stage to getstage quest1 + 10

As you see, when you put a minus right in front of a variable the variable will be negated. To acomplish this, the parser needs you to put spaces around all minuses that are operators and not algebraic signs. If you use "b-a" in the above example, the script doesn't compile; it needs to be "b - a".