I would say that it is the “good energy” we perform acts with that counts as “Good Karma” – not the acts themselves. What is determined as “good” by our ego-minds (and its collective form as societies “norms” and “morals”) is usually a mental judgment, and rarely of the highest truth – as it is said “the road to Hell is paved with good intentions”? It is also said that we don’t get to Heaven by good deeds (alone). Heaven is an internal place of consciousness – not a material place which we work our way up to by worldly acts. However, if our actions come from the pure energies of our inner hearts (that place in us that is of Heaven) naturally, that’s another matter – then we strengthen such energies in the world, and in ourselves – this is “good” karma.
“Good karma” is when you send a positive energy out into the world – a positive energy will eventually come back to you. If a man praises his wife… who praises her son… who pets the dog… who fetches dad’s newspaper – this is good karma (even if the dog chews up the paper before delivering it). On the deeper levels, it’s the “positive energy” behind the feelings that really counts as good karma, not the outward appearance of the act.
The only problem we can have with good karma is when our limited ego-minds get attached to it and wants to have it for ourselves. When it does this, we get in trouble and the flow can shut down. Just like love, good karma is an intangible we can allow to flow out of us, and receive it back with open arms. We cannot put it on our mantle place as a trophy, we cannot possesses it like a thing. When we start to do this, we turn a good thing into a bad – instead of expanding and freeing up our soul, it contracts and limits us further into our ego-mind. This is what “bad karma” does to us.