When the author allows the audience to know things that the players do not know.

The period that marks the paleolithic era is between the 250,000 to 10,000 years.

Relief sculpture - images are set against a flat background. a coin is a good example: the inscription, the date, and the figure are slightly raised above a flat surface. the ancient egyptians sometimes carved figures into a flat surface.    pro: they take significantly less time to make and do not require as much tools or skills as free-standingcons: not nearly as realistic, as it is not fully 3-d, and does not have the details that a free-standing one does.freestanding sculptures (also called  carved in the round) are not attached to any  background.  they are 3-dimensional  and fully rendered.