Wormwood, the name of the forest where blood is shed in the main characters' journey, is also the name of a destructive entity found in the Bible. This entity, described as a star, is called Wormwood (from a Greek word also translated as Bitterness) and appears to cause a plague-like (or poisoning) effect. From the Book of Revelation 8:10-11 we read "The third angel sounded his trumpet, and a great star, blazing like a torch, fell from the sky on a third of the rivers and on the springs of water--the name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter."
Test screenings reportedly did not impress Lionsgate executives and the studio decided to push back the originally planned March 2010 release date. The movie underwent reshoots in September 2010 in Shreveport, Louisiana.
Filming took place in Austria, Hungary and Croatia. Most of the principal photography took place in practical locations, with several days committed to filming on greenscreen. Principal photography was completed by April 2009, but the cast and crew re-gathered a few months later to film additional battle sequences, filming on greenscreen to save on travel. The reshoots were directed by Brett Ratner.
Season of the Witch was produced by mega producer Charles Roven. A few of the films that Charles Roven has produced and has lined up to produce are: Three Kings (1999) Rollerball (2002) Scooby-Doo (2002) Bulletproof Monk (2003) Scooby-Doo 2: Monsters Unleashed (2004) Batman Begins (2005) The Brothers Grimm (2005) Get Smart (2008) Get Smart's Bruce and Lloyd: Out of Control (2008) The Dark Knight (2008) The International (2009) Season of the Witch (2011) The Dark Knight Rises (2012) Man of Steel (2013) American Hustle (2013) Warcraft (2016) Batman v Superman: Dawn of Justice (2016) Suicide Squad (2016) Wonder Woman (2017)
Originally development in 2000 when the spec script by screenwriter Bragi F. Schut and was purchased by MGM. The project moved from MGM to Columbia Pictures to Relativity Media, where the film was finally produced by Charles Roven and Alex Gartner.