- Actor-Inspired Element: Steven Seagal personally selected every weapon seen in the film.
- California Doubling: Due to film schedule constraints, the sequences at "Chicago Summer CES" (Consumer Electronic Show) were actually filmed at the November Comdex (Computer Dealer Expo) in Las Vegas. The film crew carried press credentials and pretended to be a news show filming about the products in the booth.
- Cast the Expert:
- Joseph F. Kosala (Lieutenant Strozah) is a real Chicago ex-cop. He's been in seven of Andrew Davis' movies. He was a technical advisor on this film.
- The sword-fighting sequence was staged using Steven Seagal's own martial arts students.
- Completely Different Title: In Russia, the bootleg translation became Nico. That's fine. But for some reason bootleggers titled the following Seagal's films as sequels: Nico 2, Nico 3, Nico 4...
- Darkhorse Casting: There's a story that Steven Seagal was given the starring role due to a bet made by a studio executive that he could make anyone a star and cast his martial arts instructor.
- The Red Stapler: After the film opened, aikido experienced a boom worldwide. Steven Seagal's Los Angeles dojo was struggling before the movie. Afterward, it sold out all its classes.
- Star-Making Role: Steven Seagal.
- What Could Have Been:
- Originally, the film was about corruption on the waterfront in San Francisco. When Andrew Davis and Steven Seagal changed the story, they moved the location to Chicago.
- Seagal chose the film from a pile of scripts Warner Bros. had been saving for Clint Eastwood. It was re-written to focus on Seagal's actual backstory. Many of his stories have never been confirmed.
- Written By Castmember: Steven Seagal cowrote the script.
Trivia / Above the Law