Intertextuality

Intertextuality is the making of a text meaning by another text and is most commonly used as a literary device. It can range from directly quoting one piece of literature to being a retelling of a story.  It has been used for centuries but with today's advancements, stories and ideas can be borrowed and used almost all the time.

I found a particular essay that had many different examples of intertextuality in the Harry Potter series. Probably the most obvious example would be the headmaster of Hogwarts, Dumbledore.  He serves as a mentor much like Gandalf, the wizard from Lord of the Rings. In fact, in recent years with the growing popularity of both Harry Potter and Lord of the Rings, the two actors that play Dumbledore (Michael Gambon) and Gandalf (Sir Ian McKellan) are often confused as one another. Along with the similar characters, the two stories are also are about fantastic journeys against an evil force (Lord Voledmort in Harry Potter and Sauron in Lord of the Rings).

However that is not to say that intertextuality is limited to only literature. There have been many movies based off of classic literary works. The most common have been Shakespeare plays.

Here are just a few examples:

Hamlet? Otherwise known as Lion King.

Uncle Scar has  killed the current King, Mufasa, to become king himself. Meanwhile Simba is a young prince that must regain his proper place and save his mother and people from his power-hungry uncle.

12th Night? She's the Man. 

Viola pretends to be her twin brother Sebastian in order to play with the boys' soccer team and ends up falling in love with Duke.  Duke meanwhile is in love with a schoolmate named Olivia who is in love with Sebastien (a.k.a Viola in disguise). 

Taming of the Shrew? 10 Things I Hate About You.

A young man needs someone to date Katarina so that he can go out with her younger sister, Bianca. The man he pays to date Katarina actually finds her fascinating and falls in love with her.