Machinations diagrams are a good vehicle to capture and reason about recurrent patterns in the internal economy of games. Below you can find an overview of 13 patterns that have been documented thus far:
Produce a steady flow of resources over time for players to consume or to collect while playing the game.
Use a static engine when you want to limit players' actions without complicating the design. A static engine forces players to think how they are going to spend their resources without much need for long-term planning.
A source produces an adjustable flow of resources. Players can invest resources to improve the flow.
Use a dynamic engine when you want to introduce a trade-off between long term investment and short-term gains.