Deep in the heart of Texas, attackers closed in on banks. They swarmed hospitals. Wearing combat boots and camouflage uniforms, soldiers mounted a defense. But instead of being crouched behind buildings, the troops were hunched over keyboards.

It was in this digital battlefield where Army and Air Force soldiers participated in a training exercise to defend critical infrastructure from crippling cyberattacks, a recognition that the U.S. military is fighting in a new domain.

The Army Reserve Cyber Operations Group conducted the Cyber X-Games 2018 in San Antonio, Texas, bringing together 72 soldiers and contractors for the exercise. The in mid-June games focused on protecting areas like finance, public utilities and health care from attackers.

The goal is to “take real-world cyber-related events and leverage the information from those events into an exercise,” said Lt. Col. Michael Lewis, an officer at the Army Reserve Cyber Operations Group, in a news statement.

The games recognize how cyberwarriors in the military have a broad range of responsibilities. Last year, the Army said that the Cyber X-Games looked at how cyber could be used in special operations missions. Then, they performed a hostage rescue. This year, the exercise focused on protecting critical infrastructure. Participants required knowledge of “supervisory control and data acquisition,” a control system commonly used in public utilities and service sectors.

Working with the control system “is a big problem set in the cyber forum now and the fact that it was addressed at the X-Games to bring awareness is significant,” said U.S. Air Force Tech. Sgt. Dana Timmons, who was on the top finishing team.