Game theory is an agreement among the firms of a market about the prices to charge or output supplied.

Game theory represents a situation among the interacting firms, each of
which chooses their best strategy given the strategies that all the other firms have already been chosen.

Game theory is the study of how people/firms/countries make decisions in situations in which attaining their goals depends on their interactions with others.

Game theory is the best response strategy for a firm, no matter what strategies other firms use.

Game theory is a market structure with only one producer/seller of a good and it does not act as a price taker but as a price setter.