The agency's PWR reserve is shown in the top left corner of the user interface during missions.

PWR (or “power”) is a resource required for using most programs, and some items, weapons and augments. PWR can be gained from generator programs, Consoles, Portable Servers, some augments, and by stealing from drones.

The agency's PWR reserve is shown in the top-left corner of the screen during missions. It is capped at 20 PWR, and cannot be taken below 0 PWR. Unlike credits, PWR is not preserved across missions; the agency's initial PWR at the start of the mission depends on the game difficulty:

• In Beginner, Experienced, Expert and Endless modes, you start each mission with 10 PWR.
• In Expert Plus and Endless Plus modes, you start each mission with 5 PWR.
• When playing with custom difficulty settings, you can set the mission start PWR to any number between 0 and 20.

In the Power Relay Station side-mission, the agency has the option to sell 15 PWR for 500 credits.