1. A computer system for crafting virtual items comprising: a server computer system that registers a non-virtual physical product via a computer network and produces outputs indicative of a virtual user character corresponding to the physical product, said virtual user character being assigned to a user account that is stored on a user computer; said server computer system distributes virtual items including a plurality of different item templates and a plurality of different virtual materials into a user storage associated with a selected user account for creating a customized virtual item on the server computer system, wherein the server computer system determines which of the plurality of different item templates and which of the plurality of different virtual materials to distribute to the user storage according to calculated probabilities based on a characteristic of the virtual user character assigned to the user account and the item templates and virtual materials are earned in response to activity performed by the virtual user independent of creating the customized virtual item, wherein the calculated probabilities are based on a combination of the non-virtual physical products registered to the user account; and said server computer system creating a customized virtual item in response to actions taken by the virtual user character received on the server computer system via the computer network, wherein the server computer system creates the customized virtual item by applying at least one of the plurality of virtual materials that is stored in the user storage to one of the plurality of different item templates that is stored in the user storage, wherein the templates and the virtual materials stored in the user storage are retrieved from the user storage for use during said creating of the customized virtual item and become unavailable for subsequent use after the templates and the virtual materials are used.