Subroutine (): An ability of a piece of ice which interferes with the Runner if allowed to trigger during a run.
Subroutines are special required conditional abilities on ice. They are always marked with the symbol. When the Runnerencounters a piece of ice, the subroutines trigger; unless the Runner breaks them, the subroutines will resolve and the Runner will have to deal with the consequences.
Subroutines are abilities of a piece of ice marked by the symbol. If the Runner encounters a piece of rezzed ice and does not or cannot break its subroutines, the unbroken subroutines trigger and resolve one by one.
In addition to preventing the Runner's access to the Corporation's servers by ending his run, subroutines can pose other hazards if allowed to trigger, such as damaging the Runner or initiating trace attempts.