No one's ever really taken weed seriously. Half Baked is at the front of that line.
Essentially what Half Baked can be called is the Meatballs/Porky's/Revenge of the Nerds of the 90's. It's got that fully stupid humor that teens and frat kids go for in droves, and it deals with a topic very dear to the heart of today's youth... weed. pot. ganja. mary jane... etc. etc.
Plot is, like all films such as this, as basic and off kilter as possible... for two reasons: one, the simpler it is, the better the kids understand it; two, the weirder it is, the more potential humourous situations come out of it. In this case, the film revolves around four pothead roommates (and the guy on the couch), one of who winds up in jail. To bail him out, the remaining 3 boys decide to sell weed to raise the funds needed. Of course they run afoul of both the current druglord and the police, but everything works out okay (duh). This basic plot allowed the incorporation of a simple romance story, a heist story, the prison jokes, and a 60's Batman parody among others.
It's quite funny, surprisingly. The use of mostly comedians as the actors of the film allowed for even more humour to shine through. There were plenty (and I do mean plenty) of cameos in this (even more than Spice World), and most of them were downright hilarious. Most suprising though, was the portrayal of potheads and all the different types of people who use the stuff. It didn't glorify pot... all the time... it instead showed both positive and negative reprocussions of continual use. Of course, it was never too serious though, even the death scene was a high point of comedy (no pun intended).
If you go for the stupid humour, Half Baked is a good toke for the eyes. Even if you don't go for the stupid humour, Half Baked'll still relax ya some... plus the odour off the potheads in the theatre will loosen you up some too.