Speaking at ANZ Stadium at the Blues' captain's run on Tuesday morning, Gallen anticipated the rulebook to be thrown out the window when the two teams come together.
Gallen also expected debutants Josh Mansour, Matt Moylan, Adam Reynolds and Dylan Walker to fit nicely into the Origin arena and the hurt that comes with it.
"There's a lot of emotion and a lot of passion from both sides. We both love it, we both hate each other and at the end of the day we're trying to hurt each other," Gallen said.
"It's an Origin game and a lot of NRL rules go out the window. I'm sure there will be a lot of niggle in every single tackle. There is genuine hatred between the two sides and it will erupt. You'll see some fireworks."
"The debutants will be ready for that. They're not coming here to pull on the blue jumper and be happy to be here, they're here to make a difference which I'm sure they will."
With the intimidation factor of Origin non-existent in his mind, Gallen also quashed suggestions Cooper Cronk would be ruled out for Queensland and said they were using the veteran halfback's ankle injury as a "pawn" in their own mind games.
"He will play there is no doubt about it," Gallen said. "Cooper is not one to play mind games so I think they are using him a bit of a pawn there.
"Cooper is not that sort of a guy and I don't think he will appreciate being treated like that. He is the ultimate professional and he will be doing everything to get himself right."
Forever focused on their own backyard, Gallen said NSW's opposed session with Intrust Super Premiership outfit North Sydney Bears last Sunday night has done them the world of good.
Gallen didn't beat around the bush when detailing how the Bears knocked them off their high horse after a highly successful camp in Coffs Harbour.
"We were doing it a little bit too easy in Coffs Harbour. Having opposition in front of us brought us back a peg," Gallen said.
"We were too good in Coffs, we were going unbelievable to be honest with you. It was good to have opposition in front of us who didn't know exactly what was going on so the opposed session has really helped us."