First we visit the game properties and look for the general tab as the screenshot shows. On the bottom we find an input field where we can add multiple start parameters separated by a space.
in there we just type "-lv" without the quotes for now. It stands obviously for low violence. After typing it it got saved.

Ingame, visit the options->multiplayer category. There you find the "GORE" level.
Set it to low.

Note: This option obviously is represented by a console variable. When you have setup an autoexec.cfg where all your settings are located you can use following code:

We focus on two console commands here:

cl_destroy_ragdolls which removes all current ragdolled infected and r_cleardecals which removes all decals on walls which got added. For instance blood sprays, bullet holes and player sprays. We need to do some config stuff in the autoexec.cfg. When you did not create one yet check the section "How to create an autoexec.cfg" of this guide and come back later...


code for the autoexec.cfg


The first line creates an alias. This basicly means that when we enter "cl_de" in the console, everything in the quotes r_cleardecals and cl_destroy_ragdolls get executed.
The following lines just binds the movement keys to the movement directions plus the alias.
So when we press W, we move forward and we execute cl_de.
You are free to add cl_de to other keys actions.

Thats it.

• Go to your cfg folder of your L4D2 installation. Mine looks like this:
  
• Select any of the cfg files.
  
• Hit Ctrl+C
  
• Hit Ctrl+V
  
• A copy of the selected file appeared.
  
• The dublicate is still selected...
  
• Hit F2 to rename it.
  
• Rename it to autoexec.cfg
  
• Open autoexec.cfg with a text editor of your choise. I use notepad++.
  
• Remove all its content.
  
• Now you got an autoexec.cfg ready to go.

Your video settings got a huge impact on visibility. And visibility affects your performance as a player.
Maxed out settings
Lowered settings and low violence

Most of the video settings depend on your setup and your likings.
Shader and effect settings though should be set wisely.
High-mid shader settings will enable sun flares.
Low effect details will make tank rocks appear quite late.

My recommended settings

Before the last stand update -lv had some sideeffects:

black blood decals
green riot infected


On local gameplay, having -lv parameter active, witches will get send to another galaxy by any exposion.