Developer Commentary

Developer Commentary is an extra mode featured in many of Valve's games, including Left 4 Dead and Left 4 Dead 2. In it, a player is able to listen to audio comments made by the developers, while they play through a level in the game with a significant lack of difficulty, as all Infected will ignore the player and only attack the AI Bot Survivors. There are icons called Commentary Nodes throughout a level, which trigger a specific audio comment when the player presses the "use" key while looking at the icon. Some Commentary Nodes, when activated, will spawn objects, characters, and even scripted events. In Left 4 Dead and Left 4 Dead 2 the mode takes place in the campaigns No Mercy and The Parish, respectively.

For a more in depth look at the developer commentary in each game look at the following pages:


 * Developer Commentary (Left 4 Dead)
 * Developer Commentary (Left 4 Dead 2)