If our actions cause a certain outcome, does our intention matter when it comes to the karmic debt we're generating? If we unintentionally cause someone harm, is this still something we need to "pay off" so to speak, in future incarnations?
What about if we had ill intentions, coming from an unhealed place within our psyche, or simply didn't care about the negative outcome due to selfishness, but there wasn't much of a negative outcome for others as a result of our intentions/selfishness?
I think there are so many ideas of what karma is and how it works that you'll find different answers to this.
I personally believe, based on hearing from someone who I believe to be a Realized being, that when are within karma we can't truly understand how it works. Only when we go beyond karma can we come to truly understand it.
One idea, maybe from the Bhagavad Gita, is that any action that is done with the sense of being the doer creates karma.
For the Gita, God is the doer and we are not, but when we think we are, then we create karma. The intention of the action may effect the kind/extent of karma, but it is really the idea "I am a separate person and I am doing this action" that creates the karma; if we aren't the doer then no action creates karma.
Also, our actions could simply God working through us to bring the effects of karma into the world for someone else; impossible to know truly.
On a practical level, the idea of karma can help us to take responsibility for ourselves and our actions, which I think is the whole point. I personally don't spend much time thinking about the details because I don't think it is very helpful, beyond that.