This book serves as a comprehensive guide to modifying and creating custom content for the classic video game Doom. It details how to manipulate every aspect of the game, from character design and environmental atmosphere to audio elements and weaponry. Written by the creator of the Doom Editor software, it aims to instruct individuals without programming backgrounds on developing their own Doom games, offering creative suggestions for level design and providing shareware programs on an accompanying CD-ROM.

The book is presented as a definitive resource for Doom enthusiasts looking to delve into game modification. Its strength lies in its direct approach, authored by the inventor of the Doom Editor software, making it a credible source for technical instruction. The inclusion of the software on CD-ROM enhances its practical value for users. The content appears geared towards providing a thorough understanding of the game's architecture for creative customization.