How do idle/clicker games work?

Idle games (also called incremental or clicker games) have a unique progression system. You start by clicking to generate resources manually. As you accumulate resources, you purchase upgrades and buildings that generate resources automatically — even while you're away. This creates an addictive loop of earning, upgrading, and expanding. Most idle games feature a prestige system where you reset your progress in exchange for permanent multipliers that make subsequent runs faster. The genre was popularized by Cookie Clicker in 2013.