Attributes are basically simple data holders they contain just simple basic definition.
(Default attributes required by the system)
Sprite: this is used by the UI components like Skill Bar or Spell Book
Short Name: for now this is only used by formulas
Name: the identifier of the skill
Description: this is used by UI tooltip if its enabled.
Color: color also can be used UI components like the Character HUD
At run-time by using actions and conditionsyou have access to multiple values from an attribute:
Consumable Value: this is the variable/consumable value of the attribute. Used to track the current value of an attribute like Health or Mana. This is not used with attributes that do not get consumed, like Strength or Intelligence.
Value: this is the real value of the attribute. This is the value to read when you want to see what Strength, Intelligence, etc is, or if you want to know what is the max value is that Health or Mana type attributes can reach. This value contains both base value + bonus value.
Bonus: this is as the name suggests the bonus value of an attribute.
Last Time Modified: this allows you to verify when was the last time an attribute was modified. For example, you can create health regeneration skill that can only be triggered if last time modified of the health was 5 seconds ago.
Percent: this allows you to check how much percentage of an attribute an actor has. For example, if health is below 30% change character state to the Hurt state.
(Example of the Hurt state using Game Creator's state system)