In Prison Architect, your guards aren’t just for lollying around the prison with nothing specific to do. They can be assigned in different ways to make sure your prison’s safety levels remain high. In order to unlock this ability, you must research the Security part of the tech tree which will allow you to hire a Security Chief. Make sure to hire him and set up an office so that you can then start researching Deployment and Patrols.
With Deployment, you’ll gain a new tab at the bottom of your screen and a new way of looking at your prison. Using this new window, you can set guards to specifically hang around certain sectors of your prison, effectively becoming lookouts in all of those points. It’s a good idea to set guards to all major areas where there’s a lot of prisoner traffic in this way, rather than just leaving your guards without assigned places. This delegates responsibilities very well.