| A good deed is any action whose expected beneficial results outweigh its baneful ones. Sometimes it is easy to tell that an action is a good deed; sometimes it is very difficult -- because the results are unknown, or because the interpretation of the results as good or bad is itself disputable. Drawing the line between good deeds and bad deeds is the study of ethics.
Many years ago I was a Boy Scout and was taught to do a good deed daily. Whatever one may think of the BSA these days, I think this is still a useful aphorism to bear in mind. | 
