Imputation

...is used to designate any action or word or thing as reckoned to a person. Thus in doctrinal language...

1. the sin of Adam is imputed to all his descendants, i.e., it is reckoned as theirs, and they are dealt with therefore as guilty

2. the righteousness of Christ is imputed to them that believe in him, or so attributed to them as to be considered their own

3. our sins are imputed to Christ, i.e., he assumed our "law-place," undertook to answer the demands of justice for our sins

In all these cases the nature of imputation is the same (Rom. 5:12-19; compare Philemon 1:18, 19).