To Manage Resources
Resource management is an umbrella term for various activities involving resources. Resource management activities can be divided into two categories: production and allocation.
Resource production increases the amount of resources available. The method of production of resources varies from game to game. Many strategy games require units to transport resources from a resource cache to a specific building. Other games have resource production occur over time, and the amount produced each period is determined by the rules of the game. First-person shooters require players to collect ammunition, which is the only method of resource production.
Resource allocation is the method of determining when and how to use the resources. Many strategy games require resources to create units, create buildings, and upgrade units or buildings. Resource allocation requires the player to determine how to use resources in the most beneficial way to achieve the game goals. In first-person shooters, resource allocation requires the player to determine when to use what ammunition. Some ammunition might be more abundant but less powerful than other ammunition.
In Starcraft, players must use their worker units (SCV, Drone, or Probe) to produce resources. Worker units transport resources from resource caches to the main building (Command Center, Hive, or Nexus). Resource allocation involves the player constructing new buildings, constructing new units, or researching upgrades.
In Resident Evil, the player-controlled character collects resources by finding ammunition or herbs (for health). Resource allocation requires the player-controlled character to determine when to use more powerful weapons, like guns, at the cost of ammunition versus when to use his knife. With herbs, the player needs to decide if it is necessary to use an herb immediately, or save it in hopes of combining it with other herbs for a more powerful effect.