In the case where a combination instruction to combine a lower-ranked first game card in which a specific ability parameter is specified with a higher-ranked second game card is received, a sever executes determination processing of determining whether the first game card meets a given combination condition and, in the case where it is determined that the first game card meets the combination condition, the sever executes, as combination processing, specific ability addition processing of adding the specific ability parameter specified in the first game card to the second game card.