RIVALRIES

An ongoing relationship between (usually two) rivals who compete for superiority.

"James and Polly have a bitter rivalry due to the latter's inclusion in the Tea Time Teaser."

The characteristic of being a rivalrous good, such that it can be consumed or used by only one person at a time.

"Common goods are those which are rivalrous in consumption but non-excludable"

Any competition between two or more things or factors.

"Binocular rivalry is a visual phenomenon in which perception alternates between different images presented to each eye."