# Sources

Sources (triangles pointing upwards) are Nodes that create Resources.

As any other Node in a Machinations diagram, Sources can be **automatic** (the default), **interactive**, **passive**, or **activated once** before a diagram starts, depending on its [Activation Mode](https://machinations.gitbook.io/docs/nodes-properties/activation-modes).

An example of an Automatic Source is the steady regeneration of the protective shields of the player’s star fighter in Star Wars: X-Wing Alliance. The action to build armies in Risk would be modeled as an Interactive Source of armies, and passing Go in Monopoly would be a Passive Source of money that is triggered by a game event.

![](https://2667914601-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LGZcALyOGDKb9q0wdJ5%2F-LHHwtIXnApHuADO-eF0%2F-LHHww95fi_v1OhmQkkR%2FSOurce.jpg?alt=media\&token=23b4262d-4f9b-4dc1-8dc5-2d3f8417212b)

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The rate at which a Source produces Resources is a fundamental property of a Source, and is indicated by the flow rates of its outputs.

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{% endhint %}

In many ways, a Source acts just like a Pool without inputs that starts with a sufficiently large (or even infinite) supply of Resources. However, to model limited Sources, it is better to use a Pool with a specified number of Resources in it.

![Unlimited vs limited Source](https://2667914601-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LGZcALyOGDKb9q0wdJ5%2F-LHI-mKE7NBA2CMO7EU9%2F-LHI0kK1lqoSZd2vykrT%2FLimitedunlimitedSources?alt=media\&token=c6ca3162-3d8e-40b6-9e01-33c6da27afea)