L4D2 has three distinct ways to achieve this. Each comes with different risks and legitimacy levels.
Using autoexec.cfg and bind commands, you can create a simple latching jump script.
Example:
alias "+bhop" "+jump; wait 5; -jump; +bhop"
alias "-bhop" "-jump"
bind "space" "+bhop"
The "Wait" command is the issue. On many secure servers (including Valve official), the wait command is disabled to prevent automation. Without wait, you cannot create a reliable "full" script in pure CFG anymore. This only gives you a "spammy" jump, not true acceleration.
Verdict: Good for practice, not "Full" power.
Disclaimer: Use this only in private lobbies or single-player. I am not responsible for server bans. left 4 dead 2 auto bunny hop full
Step 1: Download AutoHotkey Go to autohotkey.com, download v1.1 (stable), and install it.
Step 2: Create the Script
Right-click on your desktop -> New -> AutoHotkey Script. Name it L4D2_Bhop_Full.ahk.
Step 3: Paste the "Full" Code Right-click the script and select "Edit." Delete everything and paste this advanced code:
#NoEnv #SingleInstance Force #IfWinActive, Left 4 Dead 2; Variable to toggle duck DuckEnabled := 0
; HOLD SPACE FOR FULL AUTO BHOP + DUCK ~$Space:: while GetKeyState("Space", "P") Send, Space if (DuckEnabled) Send, Ctrl down Sleep, 1 if (DuckEnabled) Send, Ctrl up return L4D2 has three distinct ways to achieve this
; 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
; Press F6 to kill script F6::ExitApp
Step 4: In-Game Settings
Step 5: Run it
Double-click the AHK file. You will see an icon in your system tray. Launch L4D2, hold Space, and feel the wind. The "Wait" command is the issue
To understand ABH, one must first understand standard bunny hopping.
To understand why an "Auto Bunny Hop" is so powerful, you must first understand the Source Engine (L4D2’s backbone). In standard movement, running forward has a speed cap (usually 260-300 units per second, depending on the weapon). When you jump, you retain your velocity, but air strafing (holding a directional key + moving your mouse) allows you to accelerate slightly with each successful jump.
Vanilla Bunny Hopping requires frame-perfect timing:
If done perfectly, your speed compounds: 300 ups -> 400 ups -> 600 ups -> Over 1000 ups. However, the Source Engine has a hidden penalty: stamina. In L4D2, after three consecutive perfect hops, your character starts to slow down unless you "duck" mid-air (a technique called "duck-tapping").
The problem: Human reaction time (~200ms) is too slow to hit the 0.01-second window consistently. This is where "Auto" comes in.