According to the Lamrim ie the Liberation in the Palm of Your Hand, Pabongka Rinpcohe stated that he karmic process of a non-virtuous action is complete when we have a full set of 4 components. These are: basis, intention, deed and final step. Basis is the object of the action ie a lamb in the act of killing. The intention, the topic of this discussion is further broken into the recognition, motive and the delusion. The deed is the actual action and the final step is rejoicing or the acknowledgement of the act as beneficial.
For the karmic process of an action to be complete all 4 needs to be complete even though any one is not present there must be some karmic consequences however small. Even is the object in not present, say the lamb is not there and hence not killed, the intention is still there ie the mind says "I want to kill a lamb" as the delusions is there. The delusion is great an will lead to future non-virtuos actions.
Hence, intention is very powerful. Whether the act is virtuous or non-virtuous it basically depends on the intention.
