Competition for limited resources
Players compete for resources.
Instead of direct competition as for example in a race, competition for limited resources creates pressure over a sparse resource. Competition for limited resources lets strategic behaviours emerge. For example, if the resources are spread in a area, players might try to prevent their opponents from accessing a resource by physically obstructing them.
Examples of limited resources are the available points in a system of scoring or some digital objects for which the players need to explore the space and collect them.
Competition for limited resources can be combined with economic transactions, e.g. trade or exchanges, or stealing or sabotage patterns.
Exhaustion of the resources might also act as an ending condition.
Example
MuseumScrable and its derivatives has players compete of a rather abstract resource, associations between real-world objects and digital objects.
The same concept is employed in the game Tangling, where players have to collect and attach virtual tags to real museum exhibits.