- When you sell or exchange Modules, you do not retain a copy;
- Modules disappear after you discover the Technology they were required for;
- If you use the "Sell All Modules" option at the Research Centre, you irreversibly sell all your available Modules;
- If you make an offer to exchange a Module, it becomes unavailable for 3 days. In order to cancel the offer, go to the Trade Gateway - "Caravans" tab, and select the "Delete" option in the "Loaded Caravans" section.
To unlock special Xenotype Units, you need to discover the Technologies that require unique Modules that can be purchased only with Protocrystals. These Modules can be purchased at the Black Market, "Protocrystals" section.