You are correct there is no copyright to the game per se - but - don't forget that literary and pictorial expressions associated to the game can be subject to copyright: http://www.copyright.gov/fls/fl108.html I hope you have consulted a lawyer regarding this because Taboo is published by Hasbro.

Still, let say I create a game called "Run, run" which I explain in my description as:

  "The most fun way to play monopoly on your iphone"

  "But what is Monopoly?"
  "You and your friends split into two teams. [...]"

I just copied a very popular game but changed the medium of how to play it. But then, again, it's more by curiosity that I'm asking this.