Sentence:  I have used the notion of games so far as if it were familiar to most people. I think this is justified as everyone knows how to play some games. Accordingly, games serve admirably as models for the clarification of other, less well-understood, social-psychological phenomena. Yet the ability to follow rules, play games, and construct new games is a <WSD>faculty</WSD> not equally shared by all persons. ... 
Meaning of the word marked with <WSD> tags:  An ability, skill, or power, often plural.