Method of synchronizing online game, and server device

A method of synchronizing an online game between a first mobile device and a server, the method comprising:

• providing, on a user interface of the first mobile device, at least one gameplay element;
• receiving, from a user of the first mobile device, at least one user interaction with the at least one gameplay element, said at least one user interaction resulting in at least one of a change in a degree of progress or a change in score;
• providing, to the server, from the first mobile device, during an online state, first information related to the at least one user interaction, said first information comprising the at least one of the change in the degree of progress or the change in score;
• receiving, from the server, an indication of whether the first information has been determined to be valid as requiring no loss of synchronization of the online game, or whether the first information has been determined to be invalid as requiring a loss of synchronization of the online game;
• maintaining the at least one of the change in the degree of progress or the change in score when the indication from the server provides that the first information is valid;
• and
• reverting an online game state of the first mobile device to an earlier state when the indication from the server provides that the first information is not valid.

A non-transitory computer readable medium including computer program instructions, which when executed by a server configured to exchange information related to game processing in an online game between a first client device and a second client device, cause circuitry of the server to perform steps of:

• causing the first client device to provide, on a user interface of the first client device, at least one gameplay element;
• receiving, from the first client device connected online, first information related to a user interaction with the at least one gameplay element, said first information comprising at least one of a change in a degree of progress or a change in score;
• storing the first information;
• determining whether the first information is valid, wherein determining whether the first information is valid comprises determining whether a loss of synchronization of the online game between the first client device and the second client device would result from a transmission of the first information to the second mobile device;
• transmitting the first information to the second client device when it is determined that the first information is valid;
• and
• invalidating the first information and not transmitting the first information to the second client device when it is determined that the first information is not valid.