High-end keyboards often have a function called "NKRO" called "N-key rollover" that recognizes all inputs regardless of how many are pushed concurrently. It makes sure that each input is logged and avoids "ghosting," which happens when multiple buttons are struck simultaneously and an additional keystroke might be noted.

The electrical lines from the key base to the keyboard output, which is usually a USB connection, may cross in a simple keyboard. The keypad may detect some words when you hit numerous buttons at once but not others. Ghosting occurs when data from two or more inputs is merged and a key you did not hit is registered as input.

Most computers allow numerous simultaneous inputs and have some degree of looping. For instance, a cheap keyboard might only have 5 key rollover, whereas a more costly keyboard might have 8 key rollover. This kind of rollover is also known as a "x-key rollover," where x is the total number of buttons that can be concurrently depressed and logged.

There is no restriction on the number of buttons that can be struck and logged at once when using n-key rollover. High-end keyboards with this functionality are usually found in eSports gaming computers. When playing video games, players frequently hit multiple buttons at once, so it's critical that the keypad correctly captures all of the input.