To protect your Blog from automated spambots, this plugin adds invisible formfields to your comment form.
There have been many new good ideas of fighting automated Spam in WordPress. Most of these Plugins (like the antecessor of NoSpamNX: Yawasp) change the name of one (or more) of your comment field. On the one hand, this is indeed more effective, but on the other hand, this goes to the expense of compatibility. Therefore, NoSpamNX does not change any of your comment fields, but still claims to be very effective.
NoSpamNX automaticly adds additional formfields to your comment form, invisible to human users. If a spambot fills these fields blindly (which most of all spambots do), the comment will not be saved. You can decide if you want to block these spambots or mark them as spam. Furthermore, you can put common spam-phrases on a local Blacklist or (if you have multiple Blogs) on a global Blacklist. This comes very handy when fighting against "handmade" Spam.
NoSpamNX works best with a wordpress default theme (e.g. TwentyEleven, TwentyTwelve, etc.)
Make sure your theme loads
comment_form in the Comment-Template (comments.php) according to the WordPress Codex - see http://is.gd/1lezf - otherwise NoSpamNX will not work properly!