In a general Japanese context, the word Karma denotes unvirtuous deeds and unvirtuous effects, but this is not accurate. Karma itself is neither virtuous nor unvirtuous. It simply means that when all conditions are fulfilled, the cause brings forth its effect. In other words, a virtuous cause brings about a virtuous effect and an unvirtuous cause brings about an unvirtuous effect. A cause that is neither virtuous nor unvirtuous brings about an effect that is neither virtuous nor unvirtuous. This is Karma or the law of cause and effect.

From Tathagata Abhidhamma, Book 1