A term that could be used as an insult or to take the piss when someone makes a silly mistake (a bit like 'duh' or similar) or fails something (like a test or challenge).

Originates from a game called 'Blazing Star', where the game over message reads: "You fail it! Your skill is not enough, see you next time, bye-bye"
by T.U.D October 1, 2003
When a person Fails at a mundane or easy task, These type of insults are found largely within online games. e.g. Counter Strike or WOW.

This is a more personal attack than 'Your a noob' or 'you sux!' because this insinuates that the person who it is aimed at completely fails... at everything

see also you fail at life
Example 1:

(CS Pro pwn's a defenseless noob)

Pro: You Fail

Example 2:

Person 1: d00d! i cant figure out how to make this computer like totally turn on!

Person 2: You Fail.
by Alastair Costley November 1, 2007
Increasing common 'You Fail' is used in means of shutting someone down shut down
Origins point towards people posting pictures of projects or attempts and things that have failed and commenting 'You Fail'.
You Fail has worked its use quite like the term 'Ya Mum'.
Kevin: 'Hi Paul!'
Paul: 'No Kevin, You Fail.'
Kevin: 'Ya Mum Fails.'
by Stan Dup November 5, 2007
You Fail at...(insert verb/noun here)
You use this to tell people they are horrible or can't do a certain thing.
It can be used as a joke to some, but also to make people really mad by a major insult.
Mostly it is used as a joke though.
Joke
Bob-"hey man, i fell off of the stairs"
Jim-"you fail at walking down stairs"
Bob-"rofl"
Insult
Bob-"dude, my girl just broke up with me"
Jim-"you fail at life"
Bob-"dude i hate you"
by R0botmunk7 September 17, 2009
-It's not for you
-You don't get the prize
-This ain't you farthers saiyuki

All in all, you got served and you most certainly fail it
"Why Mr Darcy, are you trying to insinuate that my womanhood can be given away at the toss of a hat, i do belive that you fail it"
by XeiXei October 17, 2004
Exclamation of which many forms exist (i.e. you fail, you fail it, you suck at life), used after the subject has failed at performing an easy, simple or mundane task.

If said straightfaced and/or casually, the effect can be greater than that of other, milder insults. However, its use and effectiveness depend heavily upon timing.

Conversely, "I fail at life" can be used to acknowlege one's own failiure.
(Person A proceeds to open their front door, but in doing so slips and falls, causing them to wipe out on their front steps.)
Person B: "Wow. You fail at life."
by The J-Spot January 16, 2005
What cool dudes say when someone's being a noob.
Noob: *spams up the boards*
Cool dude: Wow. You fail at the internets.
by Hampikizzel Fo' Shizzel June 3, 2005