Service Call summons a shopkeeper on the field. It is an ability exclusive to Merchants, and cannot be used in dungeons.
Dragon Quest III remakes
A Merchant will learn to call in business partners at level 17, and Service Call costs 15 MP to use. The skill has a variety of effects: providing a makeshift Inn to rest at, Church services (besides saving one's game), and duplicating the last item shop and weapons/armor shop the player visited. The price of the inn is 100 gold per person.
Service Call is learned by advancing to rank 7 of the Merchant vocation. The first appearance of the skill is slightly less useful than would be seen in the Aliahan adventure, as the shops will not transfer between the Upper World and Lower World. When the party goes between worlds, Service Call's wares will default to those of Weaver's Peak until a new shop is visited.