A badtrip describes when you take some sort of mind enhancing drug and everything goes bad, as opposed to good.

A badtrip occurs when one starts freaking his guts out while on the effect of drug(s). It can also happen when one loses contact with reality using a drug that doesn't normally includes that kind of experience.

The drugs that are most likely to trigger a badtrip are mosh, acid and speed (unconfirmed). The worse badtrips are mostly got on mosh and acid, while the most enjoyable ones often occurs while consuming a fair ammount of good quality hash or weed, especially mixed with alcohol.

When one has inhaled or otherwise consumed marijuana, it is fairly easy to trigger a badtrip, causing one to laugh to tears and start mumbling incoherently and not being able to stop laughing.

The first way is to get in front of the guy and do the following...

man : yo dude, look in my eyes
pothead : *laughs* mkay
*man slowly moves his hands alternatively back and forth his head and the pothead's head, leaving a way clear for vision beside both hands.*
man : you're walking in a forest, and there are trees, and then you start walking faster *speeds up hands* and you run faster and faster and faster and there are trees everywhere and trees and trees *goes on for a few seconds* and then BANG! *man gives a little hit of the palm in the forehead of the pothead* you run in a tree.

The second way is more of the same, but instead the trees are running at the pothead.

The third way is still more of the same, but the man has to place himself on the side of the pothead, mimic waves...

When something that you don't like happens.

when something goes wrong; a trip that has gone bad; when you are happy, then suddenly your are mad, unhappy, pissed off