A network game system for operating on a network a game made up of basic
content containing a basic program for executing start of a game solely
and one or more types of relevant content each containing a relevant
program corresponding to the basic program for further advancing the game
started by the basic program. The system includes a content management
section adapted to set an address of which users are not notified in one
or more content providing servers each in which the relevant program is
placed, the address for which a search is made by search means on the
network from a user terminal; wherein the content providing server sends
the relevant content placed in the content providing server to the user
terminal in response to a download request made by the accessing user.