Half-Life is a game that changed the first-person shooter genre. It takes place entirely inside the game world, without using cutscenes, and the character is not visible from the outside. The book covers how the game was created, the innovative methods used in it, and the difficulties the company Valve faced. It also touches on another Valve creation—the online platform Steam. The author shares what inspired the creators of Half-Life, why the main character is silent, how Valve found its unique style, and how Steam changed the video game market.