This is the last movie featuring legendary screen actor Sir Christopher Lee (Saruman the White) to be completed and released before his death on June 7, 2015, at ninety-three. Lee was one of a handful of cast members to star in both The Lord of the Rings and The Hobbit trilogies, and was also the only cast member of either trilogy to have met J.R.R. Tolkien.
When the movie was promoted with a panel at San Diego Comic Con, several fans camped outside the hall the day before the panel in order to get seats. In the middle of the night, the fans were woken up by cast members Lee Pace and Andy Serkis, who greeted the waiting fans and delivered autographs and photos for hours. In the end, Pace passed out from exhaustion, and shared a mattress with a fan.
In the book, everything is seen from Bilbo's perspective. The first part of the Battle of the Five Armies is witnessed by him in one chapter; the second part happens off-screen because Bilbo is rendered unconscious, but is retrospectively described to him in the next chapter. In this movie, the entire battle takes up nearly half of the running time due to several perspectives being followed.
During the confrontation between Galadriel, Saruman, Elrond, Radagast, and Gandalf in Dol Guldur, Galadriel fights Sauron using Earendil's Light. In the Lord of the Rings trilogy, she gives it to Frodo in Lothlórien.
For the scenes where Galadriel picks up Gandalf, a dummy of Sir Ian McKellen was used. This dummy was called Michael Gambon (it was even included with that name on call sheets (as seen in the appendices documentary)) because Gambon and McKellen sometimes get mistaken for one another.
Dominic Monaghan: "Merry" from the Lord of the Rings trilogy can be briefly seen during the auction scene.
Ruby Ashbourne Serkis: As a scared girl aboard a boat in Lake Town, who tries to escape from the town.
Peter Jackson: A painting of Bungo Baggins, which was put back over the fireplace, with Belladonna's painting by their son, Bilbo, after he canceled the auction for his house.