A server includes a content storage medium configured to store content data of content usable in different types of games. The server, upon a transmission request, sends content data to an information-processing device, and retains the sent content data in the content storage medium wherein sending the content data again is prohibited. The server, when the content data is sent from the information-processing device, receives the content data, assigns a new ID to the received content data in case the received content data lacks the ID, and stores the received content data in the content storage medium wherein sending the content data is allowed.