Fourth wall (ConceptTopic, 3)

From Compile Worlds

The fourth wall is a metaphorical wall between a storytelling and its audience. The term originates from the idea that on a theatrical stage, there would be three walls: the back, left and right, and so the fourth wall - which the characters should act aware of, but does not really exist - would be between the actors and the audience.

The term most often comes up in the phrase breaking the fourth wall, which refers to events where the characters act aware of the audience, as if the barring fourth wall had been destroyed.

Homestuck refers to the fourth wall instead as a fenestrated wall, as it is not behind a wall but instead behind a gigantic quad-display computer screen that the metaverse lies. Jade is advised at one point to do her best to ignore it, else terrible things would apparently occur.