Since the beginning of the systematic study of wear, many classification schemes have been devised. However, though covering the whole field in sum, they stay only loosely connected to each other and do not build a complete general picture. To this end, here we try to combine and integrate existing approaches into a general simple scheme unifying known wear types into a consistent system. The suggested scheme is based on three classifying criterions answering the questions “why”, “how” and “where” and defining a 3-D space filled with the known wear types. The system can be used in teaching to introduce students to such complex phenomena as wear and also in engineering practice to guide wear mitigation initiatives.