An interaction between two or more persons is considered a strategic interaction when:

all people involved work together to achieve a common goal best achieved through joint action.

all people involved have a clear path or action that will give them optimal results, regardless of what any other person chooses.

there is no optimum result possible for anyone in the group, so each person tries to avoid a worst$-$case scenario.

an individual's best choice may depend on what the others choose, and others' best choices may depend on what the individual chooses.