Games in general is interaction between two or more people where the outcomes of interactions depends on what everybody does and everybody has different level of happiness for different outcomes.
Games theory are strategic interactions amongst self interested agents. Often it is referred to as mathematical modelling tool. It is always interesting to analyse how interactions between agents are structured in order to lead good outcomes.
Some questions that needs consideration –
All possible actions that can be taken by the players of the game?
Does it matter if the player of the game think that the opponent is rational