Method of determining gifts of each friend user

1. An item management method that is implemented by a server system connected to a terminal device via a communication line, the terminal device allowing a user to play a game, the item management method comprising:

selecting a high-probability item that differs between one user and a friend user, the one user and the friend user each having a profile storing information on at least one high probability item associated with the one user or the friend user, the friend user being registered as friends by the one user, and the high-probability item being selected is an item already owned by the one user and which is not currently owned by the friend user;

detecting whether or not a game situation of the game played by a game execution user has satisfied an item-giving condition, the game execution user being the one user or the friend user who are playing the game;

selecting an item from a plurality of items that include the high-probability item based on a lottery, the lottery assigning a win probability for the high-probability item linked to the game execution user to be higher than a win probability of other items in the plurality of items;

giving the item selected by the lottery to the game execution user;

managing a given item and a number of given items for each of the one user and the friend user; and

transferring an item that has been given between the one user and the friend user in response to an item transfer request from the terminal device or a user terminal,

at least one of the selecting of the high-probability item, the detecting, the selecting of the item by the lottery, the giving, the managing, and the transferring being performed by a hardware processor.

2. The item management method as defined in claim 1 , further comprising:

changing a degree of friendship of each of the friend users of the one user with the one user based on a process of the game; and

setting a priority to each item, wherein

the selecting of the high-probability item includes selecting the high-probability item linked to each of the friend users of the one user based on the degree of friendship of the friend users with the one user and the priority of each item.

3. The item management method as defined in claim 2 , further comprising:

performing a given communication control process for communication between users; and

storing a history of communication between users through the communication control process, the changing of the degree of friendship including changing the degree of friendship of each friend user of the one user with the one user using the history of communication between the one user and each friend user of the one user.

4. The item management method as defined in claim 1 , further comprising:

setting preferential items of each user,

wherein the selecting of the high-probability item includes performing a primary lottery process that determines whether or not to select the high-probability item from the preferential items selected for each user, and a secondary lottery process that selects the high-probability item from the preferential items when it has been determined to select the high-probability item as a result of the primary lottery process.

5. The item management method as defined in claim 1 , further comprising:

setting a priority to each item.

6. The item management method of claim 1 , wherein the selecting of the item by the lottery includes setting the win probability of the high-probability item to be significantly higher than the win probability of other items.

7. The item management method of claim 6 , wherein the selecting of the item by the lottery further includes setting the win probability of the high-probability item to be at least three times as high as the win probability of other items.

8. The item management method of claim 1 , wherein the selecting of the item by the lottery is performed irrespective of whether the game execution user has possessed an identical high-probability item.

9. A server system connected to a terminal device via a communication line, the terminal device allowing a user to play a game, the server system comprising:

a selection section that selects a high-probability item that differs between one user and a friend user, the one user and the friend user each having a profile storing information on at least one high probability item associated with the one user or the friend user, the friend user being registered as friends by the one user, and the high-probability item being selected is an item already owned by the one user and which is not currently owned by the friend user;

a detection section that detects whether or not a game situation of the game played by a game execution user has satisfied an item-giving condition, the game execution user being the one user and the friend user who are playing the game;

a lottery section that selects an item from a plurality of items that include the high-probability item based on a lottery, the lottery assigning a win probability for the high-probability item linked to the game execution user to be higher than a win probability of other items in the plurality of items;

a giving section that gives the item selected by the lottery section to the game execution user;

a management section that manages a given item and a number of given items for each of the one user and the friend user; and

an item transfer section that transfers an item that has been given between the one user and the friend user in response to an item transfer request from the terminal device or a user terminal.

10. The server system of claim 9 , wherein the lottery section selects the item by the lottery irrespective of whether the game execution user has possessed an identical high-probability item.