A keyboard with n-key rollover, or abbreviated as NKRO, has the ability to scan each button press individually, as opposed to having the PC do it. As a result, every pressed button, or key, is noted, even if you’re pressing a bunch of keys simultaneously.
Sometimes you'll see the "n" in n-key rollover replaced with a number. That number tells you how many keys you can press simultaneously with the keyboard being aware. For example, if your keyboard has 6-key rollover, you can press six keys at once with successful input. N-key rollover is particularly relevant/helpful for gaming keyboards.
Not all keyboards come with n-key rollover, as implementing the feature comes with certain cost and design challenges.
Scharon Harding has over a decade of experience reporting on technology with a special affinity for gaming peripherals (especially monitors), laptops, and virtual reality. Previously, she covered business technology, including hardware, software, cyber security, cloud, and other IT happenings, at Channelnomics, with bylines at CRN UK.
