In March 2018, Endgame introduced Red Team Automation (RTA), a framework designed to help organizations validate their security defenses against adversarial behaviors outlined in the MITRE ATT&CK™ matrix. The RTA toolset consists of 38 scripts and executables that simulate various techniques used by adversaries, allowing security teams to assess and improve their detection capabilities. Unlike other adversary simulation tools, RTA is noted for its simplicity and ease of extension, providing a low-overhead solution for testing security measures. The framework currently covers over a quarter of the ATT&CK™ matrix and is intended to grow with community contributions. It supports the broader open-source community by offering a platform for collaborative development and enhancement of defensive capabilities. RTA scripts are designed to simulate behaviors like unusual network activity, PowerShell abuse, and persistence mechanisms, offering a practical way for organizations to measure and improve their detection coverage. By releasing RTA as an open-source tool, Endgame aims to foster community engagement and provide a resource for organizations to better understand and respond to emerging threats.