Unlike Marvel who has a well defined and established shared universe, DC seems to differ on what material belongs to what universe. I know that Arrow, Flash, Supergirl, and Legends of Tomorrow have had crossovers and seem to have a shared universe. Additionally the recent Batman films and the Superman films have been shown to share a universe; as seen in Batman vs Superman. Other series and movies however are less cut and dry. Where do movies and tv series like Constantine, Smallville, Gotham and others fall, and what relation if any is there?
The answer to this is very long, long enough that I wrote a blog post on the topic.
The summary is:
- There is a DC Extended Universe that includes Man of Steel, Dawn of Justice, and the upcoming DC movies like Suicide Squad and Justice League
- There is a TV universe called the "Arrowverse", which includes all of the shows airing on the CW - Arrow, Flash, Legends of Tomorrow, and Supergirl, as well as the cancelled Constantine and the CW Seed Vixen
- Everything else is its own universe. (Movie trilogies counting as a single "thing" for this purpose.)