decision theory 
noun [mass noun]
The mathematical study of strategies for optimal decision-making between options involving different risks or expectations of gain or loss depending on the outcome. Compare with game theory.Current practitioners make largely ad hoc use of statistics, probability, decision theory, graph theory, and tools from artificial intelligence and expert systems design....
- The other main direction of his work was to study gambling as a source to stimulate problems in probability and decision theory.
- This sort of reasoning is a simple example from the branch of logic called decision theory.