|Credit Market||Credit Vault||Alloy Refinery||Alloy Depot||Droid Hut|
Resources are the currencies used to purchase and upgrade assets. The game has four different resources; credits, alloy, crystals and campaign points.
Credits and Alloy have buildings that are used for storing and generating them. Campaign Points can be won by collecting stars during Campaigns
Credits can be acquired from the Credit Markets, completing chapters and attacking other players.
Alloy is created in the Alloy Refinery, completing chapters and attacking other players.
Crystals are a resource primarily gained through in app purchase (IAP). Another way to get Crystals is by winning the Mastery Reward for each chapter, by completing all missions with 3 stars. Small numbers of Crystals can be obtained by clearing rocks and junk from your village.
Generally it's a good idea to save your Crystals for droids, as having more droids increases the speed at which you can upgrade your base.
For more information and images see the Crystal page.