Steven Universe is a critically acclaimed Cartoon Network animated television series created by Rebecca Sugar.

Spoiler warning: No major spoilers, but some discussion of plot progression and foreshadowing.

The diagram below shows all 160 episodes of the main series classified by importance, showing the main plot lines,1 main and secondary characters, and important interactions through the course of the series. Unlike some other lists which try to identify the ‘key’ episodes, I've aimed to chart a course through the Steven Universe story line which makes sense as a complete experience without external clarification, foreshadowing, backstory, development and all.

A filled circle indicates an episode that contains important plot details or character development which are reasonably necessary to understand for future episodes. These episode titles are shown in dark colour.

An outlined circle indicates less important plot details or less significant character development that could be inferred from context in future episodes. These episode titles are shown in light colour.

Some episodes are shown with a red asterisk. These are episodes that are not strictly necessary viewing, but which I still recommend for other reasons.

From the diagram, I identified 81 of the 160 episodes as being reasonably necessary to plot or character development, with another 15 episodes with secondary plot or character relevance, and another 40 episodes with secondary character relevance only. Broken down by season:

Season Necessary episodes %
1 22 42%
2 11 42%
3 14 56%
4 12 48%
5 22 69%
Total 81 51%

This compares with other lists produced by:

It must be noted that Steven Universe is a heavily character-driven show, and all episodes are important to some extent. The exclusion of an episode from this list does not imply that the episode is a bad, worthless or totally filler episode. Any selection criteria will necessarily compromise some degree of completeness. This is simply my attempt to put together a balanced selection of episodes, a question to which there is no single ‘right’ answer.

Footnotes

  1. Spoiler warning: No major spoilers, but some more detailed discussion of particular plot arcs. For the purposes of the diagram, I've identified 3 key plot arcs. (1) The introduction, introducing Steven and the Crystal Gems, the key concepts involved, and developing Steven's powers. (2) The ‘Jasper/Cluster’ arc, beginning with Peridot's first appearance and concluding with the Cluster. (3) The ‘Homeworld’ arc, which deals with the Diamonds and Homeworld. ↩