Ice is one of the types of cards that the Runner can approach during a run. Approaching ice is the first step to beginning an interaction with it.
Page 30, Column 1, Paragraph(s) 10, Core Rule Book
Approach: The step of a run in which the Runner makes contact with a piece of ice and decides whether or not to continue the run.
The approach is
part 2 of the timing structure of a run, and it follows these steps:
2 Approach the outermost ice not already approached Edit
2.1 Paid Ability Window Edit
Page 17, Column 2, Paragraph(s) 1, Core Rule Book
When the Runner approaches a piece of ice, he must first decide whether he wishes to continue the run or jack out.
2.3 Paid Ability Window, the approached ice can be rezzed, non-ice cards can be rezzed Edit
Page 17, Column 2, Paragraph(s) 2, Core Rule Book
If the Runner decides to continue instead of jacking out, the Corporation has the opportunity to rez the approached piece of ice and any other non-ice cards.
2.4 Players check to see if the approached ice is rezzed Edit
If the ice is rezzed, then the Runner must
encounter that ice.
Page 17, Column 2, Paragraph(s) 4, Core Rule Book
If the approached piece of ice is rezzed after the Corporation has the opportunity to rez cards, then the Runner encounters it.
If the ice is still unrezzed, then the Runner automatically
passes it and continues with the run, approaching either the next ice or the server.
Page 17, Column 2, Paragraph(s) 5, Core Rule Book
If after razzing cards the approached piece of ice is not rezzed, then the Runner passes it. He then continues the run by either approaching the next piece of ice protecting the server or proceeding to the Access phase if there is no more ice to approach.