The most generic Bro Shake consists of a mutual hand-grab, then a back-pat and usually ending with a fist pound.
Variations are usually created and if the two bros are very good friends, they may have a more intricate Bro Shake.
Bob: "Holy shit, is that you Sam?"
*Bro Shake Initiated*
Sam: "I haven't seen you since you piled that chick in college Bob!"
Hugh Hefner: "Welcome to the Playboy Mansion boys, the ladies are a plenty."
*Bros walking in, each Bro Shake/ing Hugh*
Stranger 1: Thanks Hugh!
-To verify and/or validate a vocal statement
-To solidify a dare of sorts
-To make a bet
If the bro shake is broken, the offending bro is therefore assigned a single Bro-Merit.
Bro 2: Orly? Bro-Shake on it?
Bro 1: ... Oh alright, I actually just watched Stacy from her front yard...
Bro 1: Hey, that roof looks low enough to jump off of.
Bro 2: I dare you to.
Bro 1: Oh, yeah, I will.
Bro 2: Bro-Shake on it?
Bro 1: Aw man... naw...
Bro 2: I'll give you 50 G's if you bang Stacy tonight.
Bro 1: Oh hell yeah! Bro-Shake on it?
Bro 2: Yeah, because it's never happening.
Bro 1: Yeah...
Example of misuse of the Bro-Shake:
Bro 1: Dude. I had sex with Stacy last night.
Bro 2: Really? Do you Bro-Shake?
Bro 1: Yeah. I do. *Bro-Shake*
~5 minutes later~
Bro 2 (To Stacy): Hey, I heard you and Bro 1 got it on last night.
Stacy: Ew no gross. Never.
*Bro 1 is then assigned a Bro-Merit*
Used extremely often in Saskatoon's WestSide
Mac: That's respect homie....
KaZ: Who the fuck is this kid?
Mac: I don't know, but he looks like a chump...
(No "Bro Shake" offered to the chump kid.)