Game system, device and recording medium

1. A game system comprising:

a plurality of clients configured to progress a game in response to an operation by a user; and

a server configured to communicate with each of the clients, wherein

the server includes

a first storage that stores status information on a status of the game, account information of the user, and a revision number of the status information, in association with each other;

a receiver configured to receive an update request including status information, account information, and a revision number from each of the clients; and

first circuitry configured to

read out a revision number in the first storage based on the account information in the update request;

determine whether the read-out revision number and the revision number in the update request match each other;

update the revision number and the status information in the first storage based on the update request in a case where the revision numbers match each other as a result of the determination;

cancel the update request in a case where the revision numbers do not match as a result of the determination, and

each of the clients includes

a second storage into which the status information, the account information, and the revision number are written; and

second circuitry configured to

accept input of a retrieval request including account information of the user;

write, into the second storage, the account information included in the retrieval request, and send the retrieval request to the server;

write into the second storage status information and a revision number received from the server in response to sending of the retrieval request;

progress the game after restoring the status of the game based on the status information written into the second storage;

accept input of an instruction to store a current status of the game during progress of the game; and

send, to the server, an update request including the account information and the revision number in the second storage and the status information on the current status of the game based on the instruction to store the current status.

2. The game system according to claim 1 , wherein

the status information is difference information on a difference from status information relating to a previous revision number, and

the first circuitry is configured to

calculate status information by accumulating all difference information in the first storage based on the account information in the update request;

calculate a difference between the status information in the update request and the calculated status information;

store, in the first storage, a revision number obtained by updating the latest revision number in the first storage; and

write the calculated difference into the first storage as status information while relating the status information to the stored revision number.

3. The game system according to claim 1 , wherein the status information is platform-independent.

4. A server configured to communicate with each of a plurality of clients configured to progress a game in response to an operation by a user, the server comprising:

a first storage that stores status information on a status of the game, account information of the user, and a revision number of the status information, in association with each other;

a receiver configured to receive an update request including status information, account information, and a revision number from each of the clients; and

circuitry configured to

read out a revision number in the first storage based on the account information in the update request;

determine whether the read-out revision number and the revision number in the update request match each other;

update the revision number and the status information in the first storage based on the update request in a case where the revision numbers match each other as a result of the determination; and

cancel the update request in a case where the revision numbers do not match as a result of the determination.

5. The server according to claim 4 , wherein

the status information is difference information on a difference from status information relating to a previous revision number, and

the circuitry is configured to

calculate status information by accumulating all difference information in the first storage based on the account information in the update request;

calculate a difference between the status information in the update request and the calculated status information;

store, in the first storage, a revision number obtained by updating the latest revision number in the first storage; and

write the calculated difference into the first storage as status information while relating the status information to the stored revision number.

6. The server according to claim 4 , wherein the status information is platform-independent.

7. A client configured to communicate with a server and to progress a game in response to an operation by a user, the client comprising:

a second storage into which status information on a status of the game, account information of the user, and a revision number of the status information are written; and

circuitry configured to

accept input of a retrieval request including account information of the user;

write, into the second storage, the account information included in the retrieval request;

write, into the second storage, the status information and the revision number received from the server;

progress the game after restoring the status of the game based on the status information written into the second storage;

accept input of an instruction to store a current status of the game during progress of the game; and

send, to the server, an update request including the account information and the revision number in the second storage and status information on the current status of the game based on the instruction to store the current status, wherein

the server is configured to

store the status information, the account information, and the revision number in a first storage, in association with each other; and

when receiving an update request including status information, account information, and a revision number from the client or other clients, determine whether the revision number read out from the first storage and the revision number in the update request match each other based on the account information in the update request, update the revision number and the status information in the first storage based on the update request in a case where the revision numbers match each other, and cancel the update request in a case where the revision numbers do not match.

8. A non-transitory computer-readable storage medium used in a server that is configured to communicate with each of a plurality of clients and includes a first storage, the clients being configured to progress a game in response to an operation by a user, and the storage medium storing a program to be executed by a processor of the server, the program comprising:

writing status information on a status of the game, account information of the user, and a revision number of the status information into the first storage, in association with each other;

receiving an update request including status information, account information, and a revision number from each of the clients;

reading out the revision number in the first storage based on the account information in the update request;

determining whether the read-out revision number and the revision number in the update request match each other;

updating the revision number and the status information in the first storage based on the update request in a case where the revision numbers match each other as a result of the determination; and

cancelling the update request in a case where the revision numbers do not match as a result of the determination.

9. The storage medium according to claim 8 , wherein

the status information is difference information on a difference from status information relating to a previous revision number, and

the updating the revision number and the status information includes:

calculating status information by accumulating all difference information in the first storage based on the account information in the update request;

calculating a difference between the status information in the update request and the calculated status information;

storing, in the first storage, a revision number obtained by updating the latest revision number in the first storage; and

writing the calculated difference into the first storage as status information while relating the status information to the stored revision number.

10. The storage medium according to claim 8 , wherein the status information is platform-independent.

11. A non-transitory computer-readable storage medium used in a client configured to communicate with a server and to progress a game in response to an operation by a user, the client including a second storage into which status information on a status of the game, account information of the user, and a revision number of the status information are written, the storage medium storing a program to be executed by a processor of the client, the program comprising:

accepting input of a retrieval request including account information of the user;

writing, into the second storage, the account information included in the retrieval request the retrieval request, and sending the retrieval request to the server;

writing, into the second storage, the status information and the revision number received from the server in response to sending of the retrieval request;

progressing the game after restoring the status of the game based on the status information written into the second storage;

accepting input of an instruction to store a current status of the game during progress of the game; and

sending, to the server, an update request including the account information and the revision number in the second storage and status information on the current status of the game based on the instruction to store the current status, and

the server is configured to:

store the status information, the account information, and the revision number in a first storage unit, in association with each other;

when receiving an update request including status information, account information, and a revision number from the client or other clients, determine whether the revision number read out from the first storage and the revision number in the update request match each other, based on the account information in the update request, update the revision number and the status information in the first storage based on the update request in a case where the revision numbers match each other, and cancel the update request in a case where the revision numbers do not match.

12. The server according to claim 5 , wherein

the circuitry is configured to retrieve, when receiving a retrieval request including account information from each of the client devices, status information and a revision number from the first storage based on the account information in the retrieval request.

13. The server according to claim 12 , wherein

the circuitry is configured to return the retrieved status information and the revision number to the source of the retrieval request.

14. The server according to claim 13 , wherein

the circuitry is configured to retrieve status information by accumulating all difference information in the first storage based on the account information in the retrieval request.

15. The server according to claim 14 , wherein

the circuitry is configured to retrieve the latest revision number in the first storage based on the account information in the retrieval request.

16. The server according to claim 4 , wherein

the status information does not include information indicating the platform.