Role Play Attributes

There comes a time when many a gamedev sets out for adventure but first must create their own stat class. That is to say a class which captures a game "stat", or "statistic" for lack of a better word, like health, attack, defense, etc. This one is mine. Oh wait! there is a better word: "attribute." But I don't want to take "attribute" from your game, so I'll call mine IModifiableValue<T>. Consider it a sound building block for you to create your own attribute class. These attributes and their derivatives may affect and be effected by a multitude of transient things, e.g, a sword that bestows an attack advantage; a shield that raises one's defense; a ring that regenerates health. Because of that attributes ought to respect the following requirements: - An attribute's value shall be altered non-destructively. - Because so many things may alter an attribute, it shall notify us when changed. See sample scene here.