Trivia: Bill Skarsgård was purposely kept separated from the child-actors during filming, and outside of some early publicity photos, the kids never saw him until the first scene they filmed together in order to get their genuine reactions. The kids were both genuinely scared of him, but also incredibly excited after filming their first scene.
Trivia: The film is edited by Kevin Greutert, who edited "Saw" 1-5, and directed the sixth and seventh films. Greutert is one of only a few holdover crewmembers from the original run of the series to return. He said he felt an obligation to be a part of "Jigsaw"- feeling that given his past with the series, he should help usher the franchise into the new direction that the producers and writers wanted to take, while also helping to maintain ties to what came before.
Trivia: Retired make-up effects maestro Rick Baker (who did the Samara effects in the first two films before his retirement in 2015), has a small cameo as a man at the flea market in the film. While his lines were cut, he is still visible in the background of the scene. Members of his former makeup team took up the mantle and supplied the Samara effects in this sequel.
Trivia: A character briefly mentions Ryan Gosling in the film. This is a bit of an inside joke, as the film's co-writer Ryan McHenry also created a popular meme based on Gosling called "Ryan Gosling won't eat his cereal."
Trivia: "Blood Wars" has been confirmed to be the final "Underworld" to star Kate Beckinsale, and possibly the final film in the series. It was originally intended for there to be one final entry in the series featuring Beckinsale's trademark character Selene to finish off her storyline, but Beckinsale stated in late 2018 that she felt she had done "enough" films in the series and wasn't interested in reprising her role for a sixth film. After the film under-performed at the box office, there has also been no news on any future films, with series co-creator Len Wiseman instead expressing interest in rebooting the franchise as a television series.
Trivia: Lucas told Mr. Butler that his mother died when he was very young. Assuming this is true, when his dad asked him, "Is there anything you want me to tell your mother for you?" his father was planning on committing suicide or believed Lucas was going to kill him. (The empty prescription bottles suggest suicide). (01:12:48)
Trivia: Stick around for an extra scene after the credits. You see Ryan by the lake with the music box that he was supposed to discard.
Trivia: The plot of the movie is similar to Groundhog Day which is something that Carter mentions to Tree at the end of the movie. Tree's roommate's name is Laurie Spengler, which is a reference to Egon Spengler, played by Harold Ramis in Ghostbusters. Harold Ramis co-wrote and directed Groundhog Day.
Trivia: The film was completed and given an original intended January, 2015 release date as indicated by an early teaser-trailer. It was then pushed back more than a year to April, 2016. Due to negative test-screenings, reshoots and the sale of one of the production companies, it was repeatedly pushed about on the release schedule until it landed on a January, 2017 release - two years after its original planned release. However, just a few weeks before release, it was once again pushed back to June, 2017. And again, just a few weeks before its planned release in June, 2017, it was shelved indefinitely. It was eventually released October, 2017 as a free-to-watch title on Google Play for Android devices before a limited theatrical exhibition later in the month.