After expending energy, it slowly replenishes to the character's maximum limit.
Each strike costs a certain amount of energy, drawn from a pool that slowly replenishes in real time.
Vehicle health depletes when damage is taken, but slowly replenishes over time.
The timer for Freeze Time slowly replenishes, as long as the game stays in real-time.
Hunger was modeled through an abstract 'supply' value per squad; villages and/or forts would slowly replenish the supplys of nearby friendly squads.
The player starts off with a limited amount of torpedoes, which slowly replenishes itself, so players must shoot accurately.
Groundwater tends to move slowly, and is replenished slowly, so it can remain in aquifers for thousands of years.
The health meter is depleted with every punch landed but staying away from further punishment will slowly replenish it during the round.
Only a handful of city and state governments have lately begun to mandate rainwater harvesting to slowly replenish groundwater.
This energy slowly replenishes over time, but you can also purchase it with real-world cash.