The following definition is from http://www.dictionary.com.
noun, plural -ties.
The state or quality of being subtle.
Delicacy or nicety of character or meaning.
Acuteness or penetration of mind; delicacy of discrimination.
A fine-drawn distinction; refinement of reasoning: the subtleties of logic.
History/Historical. an elaborate confection, ornate in construction and ornamentation, sometimes edible but more often made and used as a decoration for a table or buffet.
Subtlety can be defined, in this context, as something definately lacking from the personalities of the creators, and most players, of the game Improbable Island.
In adition, Subtlety has been declared heresy by the ruling body of the Collateral Damage Adventuring Guild, as it implies a direct or indirect violation of Rule 37.