It was dedicated to Philip Seymour Hoffman, who died a week before filming ended. Since most of his scenes for the final two movies had already been filmed, the role was finished with other characters taking on his lines.
Effie Trinket (Elizabeth Banks) only appears briefly at the novel's end, but the film expands her role greatly. In the novel, Katniss's stylists are present in District 13, as well as Fulvia, who is Plutarch's (Philip Seymour Hoffman) assistant; Effie replaces these characters in the film. Reportedly, after seeing The Hunger Games: Catching Fire (2013), author Suzanne Collins called the director Francis Lawrence and said, "There's no way Effie Trinket cannot be in the Mockingjay films."
According to Liam Hemsworth, Jennifer Lawrence would purposely eat foods with garlic or tuna before any kissing scenes between them.
(At around one hour 9 minutes) When the "Hanging Tree" promo airs, Plutarch (Philip Seymour Hoffman) takes credit for changing the "necklace of rope" line to "necklace of hope." During filming, singers were chosen from the District 5 background actors to record the crowd vocals on the song. Production had not yet decided which line to use, so the actors recorded "rope" and "hope" during different takes.