Metrics give us data. And data can give us knowledge. Knowledge is power. Therefore great metrics can give us great power. But with great power comes great responsibility. When metrics fall into the wrong hands, they can be weaponized to destroy projects and teams. But wielded responsibly, they can improve the well-being of our product, process, and people, while shielding them from the tyranny of mismanagement. This talk will show how to recognize and avoid the use of metrics that do more harm than good, as well as how to utilize both common and innovative metrics safely and effectively.