There is a number of built-in condition types in IzPack which can be used in an installation description, which are evaluated dynamically at a given moment as soon as they are referenced, depending on the installer state, the processed user inputs and the parameters given to them:

• CompareNumerics Condition
  Set when a certain comparison operation matches two numeric values.

• CompareVersions Condition
  Set when a certain comparison operation matches two version string values ("detailed version rules").
  If the two version string have not the same number of version parts, assume to missing parts to be 0 to continue comparing at the same number of version parts. 

• CompareVersionsMajor Condition
  Set when a certain comparison operation matches two version string values ("shorter version rules").
  Ends comparing at the shorter number of version parts of both operands.

• Empty Condition
  True if a given value, file or directory is empty.

• Exists Condition
  True if a given variable, file or directory exists.

• Contains Condition
  True if certain substring or pattern can be found in a given string, variable content or file content 

• Java Condition
  Set based on a static java field or method

• Packselection Condition
  Set when a certain pack is selected for installation.

• Ref Condition
  Set when a another, referenced condition is set.

• Variable Condition
  Set when a certain value matches the value of an IzPack variable.

• User Condition
  Set when a certain user is using the installer.