Unlike the “individual diagnostics” distinguished here by apostrophes, a “system diagnostics” should focus less on the person under investigation and more on the rules and determinants of the entire ongoing process within a system. Personality tests or comparable instruments are not available for these system analyses. The focal point of a system diagnostics of social interactions and games is therefore the a priori assumed interests or preferences and their consequences, as well as the dispositions and reactions expected from the actors to intended or undertaken moves by the other side. Regardless of all calculations to be made about advantages and disadvantages, only qualitatively ordered preference structures are available for the problem situations selected and taken from normal life, on which the diagnostics must rely. The “payoffs” or utility values necessary for strategy evaluation must be supplemented or underpinned with probability assumptions in the case of uncertainty due to a lack of information, e.g., about the preferences of the opposing party.