Game system for exchanging medium in game

A game system for providing a game on terminal devices of players, the system comprising:

• a central processing unit configured to execute computer programs;
• memory storage configured to store machine-readable instructions, when executed, causing the central processing unit to execute a game program to provide the game on the terminal devices, providing the game comprises:
• storing the game program for implementing the game on the terminal devices;
• storing owned quantities of first game content and second game content owned by each of a plurality of players of the game, in association with player identification information unique to each of the plurality of players;
• storing:
• first trade condition information including a trade quantity of the first game content set by a first player among the plurality of players, and player identification information of the first player;
• and second trade condition information including a trade quantity of the second game content set by a second player among the plurality of players, and player identification information of the second player, in association with each other;
• generating trade rate information including the trade quantity of the first game content and the trade quantity of the stored second game content;
• presenting the trade rate information in the game being played by a third player among the plurality of players;
• receiving a first trade condition updating request including at least one of a trade quantity of the first game content and a trade quantity of the second game content set by the third player;
• updating the first trade condition information so as to include the trade quantity and the player identification information of the third player included in the first trade condition updating request when the first trade condition updating request includes the trade quantity of the first game content and the trade quantity of the first game content is greater than the trade quantity included in the first trade condition information, and updating the second trade condition information so as to include the trade quantity and the player identification information of the third player included in the first trade condition updating request when the first trade condition updating request includes the trade quantity of the second game content and the trade quantity of the second game content is greater than the trade quantity included in the second trade condition information;
• and
• updating the owned quantities of the stored first game content and the second game content, based on the stored first trade condition information and the second trade condition information.