Book excerpt: Defeat cancer before it develops. Prevent crime before it happens. Get the perfect job without having to know the right people. Algorithms turn long-wished-for dreams into reality. At the same time, they can weaken solidarity in healthcare systems, lead to discriminatory court judgements and exclude individuals from the labor market. Algorithms are already deeply determining our lives. This book uses illuminating examples to describe the opportunities and risks machine-based decision-making presents for each of us. It also offers specific suggestions for ensuring artificial intelligence serves society as it should.