Out of the box

"Out of the box" is an expression that describes nonconformal, creative thinking.

The term is used as an adverb to describe the thinking or as an adjective to describe the ideas.
The term is said to derive from a famous puzzle created by early 20th century British mathematician Henry Ernest Dudeney, in which someone is asked to interconnect nine dots in a three-by-three grid by using four straight lines drawn without the pencil leaving the paper.
In order to be successful, the puzzle solver has to realize that the boundries of the dot array are psychological. The only way to solve the puzzle is to extend the lines beyond the artificial boundry created by the nine dots.