This command will switch the current map you are playing on to the specified map. To load a map from the start menu, use the map command. Find a list of all map IDs at commands.gg/l4d2/map.
The syntax for the changelevel command is as follows:
changelevel [map id]
This command has the following arguments:
|Map ID||The ID of the map you wish to switch the game/server's to. Find a list of all map IDs at commands.gg/l4d2/map.|
Find below working examples of the changelevel command.
This cheat would change the level of your current game to the Dark Carnival Concert map.