Book excerpt: Throughout the 1990s, artists experimented with game engine technologies to disrupt our habitual relationships to video games. They hacked, glitched, and dismantled popular first-person shooters such as Doom (1993) and Quake (1996) to engage players in new kinds of embodied activity. In Unstable Aesthetics: Game Engines and the Strangeness of Art Modding, Eddie Lohmeyer investigates historical episodes of art modding practices-the alteration of a game system's existing code or hardware to generate abstract spaces-situated around a recent archaeology of the game engine: software for rendering two and three-dimensional gameworlds. The contemporary artists highlighted throughout this book-Cory Arcangel, JODI, Julian Oliver, Krista Hoefle, and Brent Watanabe, among others –- were attracted to the architectures of engines because they allowed them to explore vital relationships among abstraction, technology, and the body. Artists employed a range of modding techniques-hacking the ROM chips on Nintendo cartridges to produce experimental video, deconstructing source code to generate psychedelic glitch patterns, and collaging together surreal gameworlds-to intentionally dissect the engine's operations and unveil illusions of movement within algorithmic spaces. Through key moments in game engine history, Lohmeyer formulates a rich phenomenology of video games by focusing on the liminal spaces of interaction among system and body, or rather the strangeness of art modding.