Killing and planing to kill As to Buddhism killing is wrong and planning such things is also wrong.
So what is the difference between the Karma of a person who killed someone and a person who only planned but never killed.
Je Tsongkhapa differentiates between (1) karma that is done (2) and karma that is accumulated. Between the two, there are four possibilities.

1. Done, but not accumulated. Tsongkhapa states:


  Killing that is karma which you have done but not accumulated is seen
  in the following cases: that done unknowingly, that done in a dream,
  that not done intentionally, that which another person forced you to
  do against your will, that done only once and then regretted, [and so forth]



2. Accumulated, but not done. Tsongkhapa writes:


  Killing that is karma that you have accumulated but have not done is
  seen in the following case: you investigate and analyze for a long
  time in order to kill a living being, but you do not kill it.



3. Done and accumulated. Tsongkhapa writes:


  Killing that is karma that you have done and accumulated is seen in
  all the killing not included in the previous two permutations.



4. Killing that is karma that you have neither done nor accumulated is whatever is not included in the above three. Tsongkhapa does not give example.


He further explains that karma that is not done and accumulated (the third) is karma whose result you will not definitely experience.

The Levels of Yogic Deeds (Yogācārabhūmi-śāstra):


  Karma whose result you will definitely experience is that consciously
  done and accumulated. Karma whose result you are not certain to
  experience is that consciously done but not accumulated.


Further debates settles on the meaning and reason of such a statement: karma that is done and not accumulated, for instance, is not as heavy as that which is done and accumulated. The weight of karma is one of the five factors that determines the time and the likelihood of its ripening.