Admin System
With the Admin System, you are given Admin control. You can spawn Infected, give Survivors weapons/items, kill/revive Survivors, change Convars, change the timescale, and much, much more!
All of this is done server-side via chat triggers. If you don’t have a server, all you need to do is host a Local Server and you should automatically be added as an Admin. If you want to give other players Admin control, you can type "!add_admin nick" if they’re playing as Nick, or "!add_admin <playername>" to add their Steam ID to the admins.txt file.
If you have a server, you’ll need to manually upload an admins.txt file to your left4dead2/ems/admin system folder. If one doesn’t exist, create one.
Click here for a complete list of available commands.
Check out Admin System Radial Controller created by jyrka98, for use with the Admin System.