Game theory is a tool that’s used to “map out” particular situations and figure out what is likely to happen under various scenarios.
In some cases game theory is employed using mathematical equations that capture the specifics of a situation. In these cases, the equations can be used either to solve for optimal solutions and/or to generate simulations to see how the situation plays out under different scenarios.
However, game theory can also be employed using less rigorous methods. Most situations can be mapped out visually and textually, and then one can use those mappings to better understand situations and draw conclusions.