I'm not sure about gold needed to buy his soul back, but the popular theory is that it is his soul itself. Apparently the bandaid on the back of his neck is where the devil removed his soul (claims say this is supported by the bible, but it is not- nowhere in the bible does it describe the back of the neck as the place of removal). The kids in the apartments are "satans helpers" and Jules and Vincent are sent to recover the soul because Wallace changed his mind (or got ripped off?). The so-called "evidence" of this theory is in the combination on the briefcase ('666' naturally, for the devil's briefcase) and the fact that Jules and Vincent were saved by the 'miracle' (they were saving a soul, it was divine intervention). There have been many theories about exactly what it is, this one is fun but probably not Quentin Tarantino's intention. According to the man himself, this is merely a MacGuffin- or something thrown into the plot without bothering with specifics or purposely making the audience wonder and produce their own theories. Some of the other theories include a small nuclear bomb (referance to some movie that I dont recall), the oscar Quentin hopes to achieve, the diamonds from Reservoir Dogs, etc. All a bunch of phooey, I'll tell you what was really in it- Jules came right out and told you: Marcellus Wallace's dirty laundry. The reason it shines so brightly is because Jule has got the magic of Clorox. (PS: we all assume 'dirty laundry' was his sarcastic answer but it is possible he's referring to stolen money- sometimes known as dirty laundry because it has yet to be laundered)

Isn't it obvious? The events in Pulp Fiction are an early iteration of the matrix. Vincent and Jules are agents - dodge bullets. Butch is the one - badass with a katana. Marsellas is a strange kind of mix between Morpheus and the Architect. et cetera. The case contains the key to zion. I realize that Pulp Fiction was created long before the Matrix, but it's still a neat idea.

This is the most debated movie question of the 90s. In fact, the MTV movie awards had a contest to find the most creative answer to the question---the winner was the one who proposed the "soul" theory. However, Tarantino (the director/screenwrite) wrote it in as a McGuffin (refrence the original screenplay), an old Hitchcock trick. A McGuffin is a movie symbol, character, or plot deviation that means nothing. It is meant to draw attention to itself, and, as it did in Tarantino's case, puzzle the audience. The suitcase was one, big publicity stunt. When asked about the contents, Tarantino once remarked, "Two lightbulbs and a battery. Next question?"

Ever thought it was the title belt for the boxing match? The four dudes that Vince and Jules meet stole it and were ratted out by Marvin (the black guy who gets his head blown off). My two cents.

What it contains is what it needs to be in order to keep you permanently interested in 1) the movie and 2) the case; in that order. But literally it was 1) foil, 2) 2 orange-hue mini-bulbs, and 3) some batteries (Tarantino says this)

I saw an interview with Quentin years ago discussing this. Apparently it WAS Marcellus Wallace's soul. Quentin also referenced the band aid on the back of Mr. Wallace's head. Historically, that is where the devil would remove one's soul...

No.The movie closes with the opening scene, ergo it comes full circle. The movie has a sense of completion with the way it was created. I think, on the subject of the briefcase, that ,as stated before, it was merely a McGuffin. The "Devil" theory is just a major coincidence. What I pieced together through the dissection of the film was, every thing that occurred was just a momentous butterfly effect. The events coincide. Look at the first definition of the word pulp, A soft, moist, shapeless mass of matter. The movie, though very well directed and produced, really has no meaning behind the items of witch we find to be of consequence. It's just one thing leading to another that causes another occurrence. However, the idea of it all meaning something is quite intriguing. It is just a balance between forces, a equilibrium caused by the natural laws of the galaxy.