What is going on with the dialogue?

In my opinion, the dialogue is out-of-place and ridiculous. I understand what the director was trying to do with the dialogue.

I cannot believe that anyone in high school acted nor talked like this in 2006

So why did you go see the movie? If you wanted realism you could go listen to kids talk at school for free rather than pay to sit in a theater

Johnson was a fan of Dashiell Hammett and writers like him that wrote a lot of the "hard-boiled" crime fiction in the 30's and 40's which became the basis for most films noirs. Therefore, there's quite a bit of jargon and colloquilisms used. Add on the fast paced nature of the dialogue delivery and you have a movie that you need to pay VERY close attention to if you want to understand everything that's going on. It took me three viewings before I really nailed down the plot intricacies and I had to use earbuds. This being said, if you don't care for film noir, you won't get this film at all. Just image Double Indemnity taking place in a high school setting and things will make more sense.

The dialogue isn't realistic. It isn't how people talk in high school... It's a noir. The dialogue is, for the most part, a throwback to detective films of the 50's and 60's. If the dialogue was similar to every other high school film, people wouldn't be talking about years later.

I agree it was like Sin City dialogue.

The dialogue- the whole film really- is more of an omage, a tribute to film noir. I, and many others, of course had a hard time understanding it. But it was done, in my opinion, with such precision and passion that it worked. It exists in its own universe, its own world, and it pulls it off. One of the line I can't stop myself from laughing at is excellent. "If you've got disciplinary issues with me then write me up or suspend me, and I'll see you at the parent-teacher conference." I love that line, its great and delievered with a straight face. Again, think of it as a tribute to Bogart films. Consider the scene where (very minor spoiler) Brendon attacks Dode early on. First look at the visuals, the way he slaps his face side to side, the sound it makes, and the shot order. Very old fashioned, before one of the best lines in the film, something along the lines of "You Hash-Hags want to start something remember I got all five senses and I slept last night that puts me six up on the lot of ya." Of course it's not realistic, but it's fun.

The dialogue pays homage to Raymond Chandler and Dashiell Hammett IMO specifically The Big Sleep and The Maltese Falcon. IF you watch bot of those a few times and get the dialogue fixed in your head and then watch Brick you can see some of the scenes for both of those movies remade in Brick. The DA scene from The Big Sleep is about a 75% match to the Ass-VP scene in Brick along with the Eddie Mars confrontation scene in the middle of the Big Sleep is close to the confrontation scene with Tug. Also might be noticed is how Laura and Brigid O'Shaughnessy are kinda a similar person using who ever they can to get what they want.

I can see how it's difficult to follow and with out having seen those two movies or having been much in to those two authors it can be hard to appreciate, i had wanted to see Brick for a while and happened to see it after going on a Noir binge and it only helped me to like the movie even more.

I could not agree more. Its dialog is stuck somewhere between old school gangster speak (which I feel is what the intent was, a nod to that era) and the traditional mob style movies. However, it is too labored. It isn't working. When you watch an old film noir period piece, it makes sense because people actually spoke that way. The same can be said for mobster movies. This however does not flow. The dialog becomes a speed bump which slows down the entire flow of your senses and you try and take it in. I want to like this, but it becomes fatiguing. I love some of the visuals but I did not finish it. I did not care enough about the characters to try and deal with the language.