- Could it be Elvis's gold suit, seen worn by Val Kilmer (as Elvis) in True Romance?
- The most persistent theory (most usually attributed to a friend of a friend who saw it posted on a message board by someone whose brother had read a report of a radio interview with Tarantino himself) is that it is Marcellus Wallace's soul. The story goes that when the Devil takes a person's soul, it is removed through the back of the head (this isn't part of any known religion, but this is what the message board posters say). When we see the back of Marcellus's head he has a Band-Aid covering the precise spot indicated by tradition for soul removal. Perhaps Marcellus sold his soul to the devil which would also explain why the combination to open the briefcase is 666.
- Quentin Tarantino has said that the band-aid on the back of Marsellus Wallace's neck had nothing to do with an allusion to the Devil stealing Marsellus's soul... but that the actor Ving Rhames had a scar on the back of his neck he wanted to cover up.
- Or could it be simply a 20-watt light bulb?
- According to Roger Avary, who co-wrote the script with Quentin Tarantino, the original plan was to have the briefcase contain diamonds. This seemed neither exciting nor original, so Avary and Tarantino decided to have the briefcase's contents never appear on screen; this way each filmgoer could mentally "fill in the blank" with whatever struck his or her imagination as best fitting the description "so beautiful". The orange light bulb (projecting shimmering light onto the actors' faces) was a last-minute decision and added a completely unintended fantastic element.
- In a radio interview with 'Howard Stern' in late 2003, Quentin Tarantino was asked by a caller the contents of the briefcase, and he answered, "It's whatever the viewer wants it to be."