This document discusses pattern engineering for functional clothing. It begins with an introduction that defines functional clothing as garments designed for a specific purpose beyond basic coverage and protection. The factors that affect pattern engineering for functional clothing are then outlined, including body shape, garment fit, fabric characteristics, and end use. Several examples of functional clothing are then analyzed in more detail, specifically work wear coveralls, sportswear, bulletproof jackets, and clothing for the elderly. For each, adaptations to standard patterns are described to accommodate the intended use or user needs. The document concludes by emphasizing pattern engineering as key to developing purposeful, efficient, and aesthetic functional garments.