This report by ACAS explores the rise of 'algorithmic management' in the workplace, analysing both its practical and ethical dimensions. It investigates where and how algorithms are being implemented, their potential to enhance workplace outcomes, and the unintended consequences that might arise. The report addresses future risks and opportunities posed by algorithmic management, including its potential impact on employment relationships. It provides guidance on how responsible employers should approach and discuss the use of algorithms with their workforce to balance innovation with ethical considerations.