King, the maker of Candy Crush Saga, now uses AI to help design and test virtually every level in its games before they reach players. AI-controlled bots play each level thousands of times in about five minutes — replacing a process that once took human testers a week — to check difficulty, find bugs, and suggest adjustments. This practice began around 2019 and accelerated significantly through 2024. In July 2025, approximately 200 King employees — including many level designers — were laid off, with sources saying AI tools had replaced their roles.

King's AI level design system works in two parts: automated playtesting bots that simulate thousands of player runs to assess difficulty and detect technical issues, and an AI "co-pilot" that suggests level adjustments in real time during the design process. The playtesting component runs on Google Cloud using TensorFlow, Google's machine learning framework. Results reported at GDC 2024 by King's Director of AI Labs include a 50% acceleration in level development speed and a 95% reduction in manual fixes needed after release. The bot-based approach traverses over 4,500 levels automatically. King developed these capabilities in-house from approximately 2019 and supercharged them with the June 2022 acquisition of Peltarion, a Swedish machine learning startup. The July 2025 layoffs — affecting level designers, user researchers, and UX staff — were described by internal sources as a direct replacement of human roles by the AI tools those same workers had helped build.