Interludes are chapters narrated from the point of view of a different character to the main narrator, Taylor (excepting two arcs, all normal chapters are from her point of view). This is not always the same character throughout the interlude. They are normally in third person as opposed to the usual first person. Interludes occur at the end of each arc, and Wildbow has added more in the middle as Donation bonuses, released whenever a certain donation milestone is reached.
Generally characters only feature in one interlude, making a return if they have gone through a significant shift in characterization, with structural exceptions for multi-part chapters and whole arc interludes, see below.
They are important to the main storyline - Cauldron was first revealed in an interlude, and the interlude from Scion's POV is incredibly relevant to the following chapters. Often, they are used to further the plot in ways the main characters don't realise, or simply to add colour to the Wormverse. Many interludes feature characters who were considered as protagonists for Worm, and so they are very detailed and have interesting backstories rather than simply being plot dispensers.
- An early interlude is from Brutus' point of view, and is written as though it were a transcript of his thoughts.
- There is an interlude that is written as a series of extracts from forums on Parahumans Online, where many of the posters are thinly-disguised versions of commentators on the main story.
- Often, interludes are where some of the biggest reveals happen. Some very spoilery examples (in no particular order) are Dragon being an AI, Defiant leaving to fight the Slaughterhouse Nine, Scion's story told from the perspective of the homeless man who influences him, Scion's story from the perspective of Scion, Cauldron's goals and motivations, the Triumvirate working with Cauldron, Eidolon's powers fading, and Eden's existence.
- Had Wildbow not received more donations, Ignis Fatuus would have had a larger role in the story, serving as a catalyst for Skitter investigating the setting's lore earlier than she did in the canon story-line. Consequently, Worm would have been far shorter.