This ethnographically based article investigates the simulated enactments European police forces undergo in mock cities in order to train for protest policing. From a perspective grounded in cultural sociology, the analysis focuses on the rubber brick used in these simulations as a substitute for the stones that protesters sometimes hurl at police. It looks at the brick as a cultural materialisation that marks a specific form of police training, as well as policing more generally. By following the stone’s trace, the article argues that the brick acts as a medium that reflects police action: It derives its meaning from the imaginary of the demonstrators and protesters as violent, and sometimes even as hostile, in the sense of forces which should be met with a combative police reaction. Thus, the stone creates a self-image of the police characterised by toughness, courage, and strength. The thorough article adds to the research about protest policing by offering the first investigation of the meaning of simulated training for police forces.