Dream-Sharing is the practice of manufacturing a dream and bringing one or more people into that new dream world. While dream-sharing, the Dreamer creates and controls the world, while the Subject populates it with both people and information. Dream-sharing was first utilized by the military to provide a realistic training method for soldiers, in Project Somnacin. It can also be used to commit Extraction by stealing information and Inception by planting information in the form of an idea into the mind of the subject and making the subject think that the idea is their own. Miles brought Dom and the others into dream-sharing to prove to them that their creativity was limitless.
To initiate dream-sharing, special medication is needed. Somnacin is one of the drugs used for this purpose.
Overexposure to dream-sharing can cause an individual to be unable to dream naturally. Many people who can no longer dream must use a PASIV Device if they wish to dream while they sleep.