A phrase used on Internet forums to counter the vast range of unverifiable claims made by users. Often these claims involve personal brag-worthy accomplishments, extraordinary or rare sights/occurrences, and tales relating to alcohol or drug use.
Guy 1: Dude, I drank four bottles of bourbon last night, then hooked up with 4 chicks at the same time, then Donald Trump came to my house and gave me a million dollars!
Guy 2: Pics or it didn't happen.
A phrase used primarily on online forums stating that the person refuses to believe the thread creator's claim unless it is shown by a photograph for proof.
I got 73 kills in a single game on Call of Duty 4 and it wasn't even on Shipment.
An internet slang representing the impeccable state of expression;
a. Pictures or Shut the f**k up
b. Alt. Pictures or don't even bother completing your conversation.
a. My wife just recovered from a lengthy breast implant operation; "Wife? - Pics or stfu!"