To enable "Auto Bunny Hop" in Left 4 Dead 2 (L4D2) , you generally need a script, a plugin, or an add-on, as the base game does not have a single native "autobhop" command like newer Source engine titles.
Check out these guides to see auto bunny hopping in action and master the movement techniques: Left 4 Dead 2 - How To Bunny Hop (Bhop Mechanics Explained) L4D2 AutoBhop Explained [2021] Easy Bunnyhop Tutorial | Left 4 Dead 2 In Left 4 Dead 2
And yet, to dismiss the script as mere cheating is to miss its deeper, almost artistic, appeal. The "auto bunny hop full" is an act of player-authored emergent gameplay. It is a testament to the enduring desire to push against a system’s boundaries, to find flow in the machine. When executed perfectly, the screen blurs, the sound of gunfire recedes, and the only audio is the rhythmic thump-thump-thump of perfect landings. It is a trance state, a kinetic meditation. In a game about relentless, oppressive pressure, the bunny hop offers a paradoxical escape—not from the zombies, but from the feeling of being grounded. For a few glorious minutes, the survivor is no longer running away from death; they are dancing alongside it, forever one step ahead, a skipping stone refusing to sink.
; Press F3 to toggle auto-duck (makes "full" possible) F3:: DuckEnabled := !DuckEnabled if (DuckEnabled) TrayTip, L4D2 Bhop, Full Mode ON (Auto duck), 1 else TrayTip, L4D2 Bhop, Full Mode OFF, 1 return