This week, the GDC Vault has debuted a special selection of free lectures from Portal and Half-Life creator Valve Software, with topics including the studio's use of biofeedback, a look at Left 4 Dead's development, and the design philosophy behind Half-Life 2.
These talks join the recently released free videos on the GDC Vault, which include the GDC 2011's classic postmortem series, as well as lectures and panels from speakers such as Playdom's Raph Koster, GDC founder Chris Crawford, and more.
The following free lectures include video, audio and slide-based highlights from Valve Software's sessions at a handful of different Game Developers Conferences, with talks dating from 2011 back to 2004.
The first lecture offered for free in video form is a GDC 2011 session from Valve veteran and experimental psychologist Mike Ambinder, titled, "Biofeedback in Gameplay: How Valve Measures Physiology to Enhance Gaming Experience." This session examines how information regarding a player's physiological states can help developers "explore new avenues of gameplay and to improve in-house playtesting processes."
Using Valve's own Portal 2, Left 4 Dead 2, and Alien Swarm as examples, Ambinder explains how the studio measured players' skin conductance response, heart rate, and eye movements to design titles that effectively toy with player's psychological limits.
Next, a newly free GDC 2009 talk video, "From Counter-Strike to Left 4 Dead: Creating Replayable Cooperative Experiences" features Turtle Rock founder and Valve designer Michael Booth on the high-level design of the studio's cooperative zombie shooter.
Booth provides some background on the game, and explains "how it evolved from Counter-Strike, and the importance of procedural systems such as the AI Director in creating replayable and compelling cooperative experiences."