What is N-Key Rollover (NKRO)?
N-key rollover, referred to as NKRO, is a feature that appears on many mechanical keyboards. It allows the user to press multiple keys simultaneously, recording each press separately. This is especially useful for gamers who press synchronized keys.
What does N-Key Rollover do?
If your keyboard features NKRO, it means that each key you press is recorded separately. So, if you press three character keys at once in a text document, all the characters will be displayed on your screen.
However, there can be limits to the number of keys you can press. This is represented by the letter "n" in the pass of the n key which is replaced by a number, for example 6-key rollover (6KRO).
Full N-Key Rollover keyboards allow you to press all keys simultaneously; mechanical keyboards benefit from this feature more than membrane keyboards.
Common Types of N-Key Rollover
Mechanical keyboards are manufactured to include different types of N key pass. This can range from two to unlimited. Here is a breakdown of the most common types:
2KRO (2 key pass)
6KRO (6-key rollover)
10KRO (10-key rollover)
14KRO (14-key rollover)
NKRO (full pass of the n key)
Is N-Key Rollover the same as Anti-Ghosting?
It is common for NKRO keyboards to feature anti-ghosting. If you press more keys at a time than your keyboard can handle, an unpressed key may be incorrectly registered. The Anti-ghosting feature prevents this from happening by blocking the registration of additional keys.
For example, on a 3KRO keyboard with anti-ghosting, if more than three keys are pressed simultaneously, this will prevent a fourth key from recording. If your keyboard doesn't have an anti-ghosting feature, you'll probably see five keystrokes, although only four are pressed.
What is the advantage of NKRO keyboards?
Previously, NKRO was possible only with a PS / 2 connector. Now, PS / 2 connectors are less common, but they can still be used with NKRO keyboards if you use an adapter. Instead, modern mechanical keyboards have the ability to feature NKRO via USB.
How NKRO is useful for players
Player-oriented mechanical keyboards often feature NKRO since some types of games such as combat and FPS require very precise keystrokes and multiple keys to press simultaneously.
Tekken 7, for example, requires pressing key combinations such as F, D, 2 and 1 at the same time to carry out an attack. If your keyboard is limited to 2KRO or 3KRO, it will not be possible to launch this movement.
Aside from feeling more immersed, consoles that lack NKRO are one of the main reasons why fighting game lovers opt for the fighting baton .
While most premium mechanical gaming keyboards feature a full n key extension, it's not necessarily a selling point that gamers should follow. There are very few games that require more than 6KRO, and unless you're using the keyboard for many players, there's no need for anything bigger than 10KRO since you only have 10 fingers.
NKRO can be used outside games
Although there are a limited number of apps that require you to press multiple keys simultaneously, NKRO has its place outside of games.
One example is music creation software. If you don't have a MIDI keyboard, you can use your computer's mechanical keyboard as an alternative. This will allow you to press several keys at once, allowing you to create and produce music.
How to test NKRO on the keyboard
Aside from checking the manufacturer's specifications to see what the n-key rollover keyboard has; you can easily test it with a script app like Microsoft Word.
Start by pressing two keys at the same time, jotting down the keys you press, then increase this by one and compare with the keystrokes recorded on your screen.
If you expect NKRO from the keyboard but don't detect the correct number of keystrokes, make sure NKRO is activated. Some keyboards require the NKRO function to be triggered using a key combination or via keyboard software.
NKRO can benefit you
If you are already planning to invest in a mechanical keyboard, you will probably find one suitable for you that also features an N-key extension.
Even more expensive mechanical keyboards can use NKRO; you just have to decide whether a mechanical keyboard is the right choice. If you are a writer or gamer, it is worth spending a little on the NKRO keyboard to ensure accurate response.