It's usually used when you are surprised to learn something. Other uses are to add how serious you are being about something. The last and most obscure usage is to explain the status of a couple. They are "For Realsies" if they are officially dating.
Usage 1:(shock)
"Koalas aren't bears they're marsupials!"
"For realsies?!?"

Usage 2:(add sincerity)
"I have always dreamed of being a plumber"
"Are you serious?"
"For realsies."

Usage 3:

"Did you here Jack and Jill are for realsies now?"
"For realsies?!?"
"For realsies."

by No credit August 10, 2007
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For Real; This shit is real; How reals are you keepin it?

Slang for hey ho hows your father bingo bango bongo
"This pepsi tastes like shit"
"For Realsies."
by Gregzzies March 19, 2007
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The same as fo'real but was instead created by Crabstickz; from Youtube, in his last 'Advent Calundah' video before Christmas when almost falling over.
"I nearly fell down then. Fo' Realsies."
by InYourFaceee December 24, 2009
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Similar to action of popping a wheelie, in the way that wheelies rule. A wheelie is pretty cool and so if you can do one, you are in fact pretty cool. So it is like an emphatic "for realsie", meaning you have done such a cool "for realsie" you are cool. Something that is a "for realsie" with a bit extra "real".
Dude: "Dude! My ex just tried to weasel back into my life!"

Dudette: "You need to pop-a-realsie and tell her you got a sex change or something! It's a trap"
by MurderSuicidePactByPinkySwear December 8, 2009
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