The question is a rite of passage for any viewer catching up on the Dressrosa arc:

Gear 4 isn't about looking cool; it's about functional chaos. Luffy compresses his arm into his torso, then unleashes the —a punch that uses the tensile energy of his rubber body plus the hardness of Haki plus the rebound of compression. It’s a punch that doesn't just hit you; it warps the air pressure around it.

"Hey, have you been keeping up with One Piece lately? I'm on episode 600-something and I'm still waiting for Luffy to unlock Gear 4. I know it's a game-changer, but I forgot exactly which episode it happens in. Can someone remind me? Is it around episode 700 or so? I've heard it's one of the most epic moments in the series. Anyone know the exact episode number?"

While Gear 4 first appeared in , Luffy has since unveiled multiple variations to deal with different types of enemies: