There are many listed skills but an infinite number of potential skills exist that can be used depending on the setting. Skills have three levels of specialization. The first is the general skill, the next is the first specialization which consists of a certain use of that skill, and lastly is the second specialization which is a certain use of the first specialization. The first level ranges from 0-33, the second from 0-25, and the third from 0-16.
A list of skills normally used in Infinite Roleplaying can be found here.