Hi

Just wondering how does a decker doing overwatch can affect a security rigger?

Can he just go in the system and crash him or black hammer him?

a decker with the right hardware and software can affect a security rigger. the rules for it are in the rules for security rigging, in R3 or R3R. it basically allows a decker to mimic a rigger's abilities; the decker can't use black hammer or any of his other normal programs against the rigger.

A decker can't perform overwatch without booting the rigger out of the ccss system. A decker on matrix overwatch wouldn't even be noticed by the security rigger because they are on two different networks that don't overlap.

they can overlap in function if say both the host and the ccss controls the door and access the cameras. still, most likely the connections are seperate. therefor a decker can edit the cameras in the matrix and not affect the riggers view of things. and most likely the rigger have override of the matrix based security if he notices anything wrong. so if the rigger locks the doors, your best bet is to either take out the ccss (if you pull it of you have a nice tool to use against any guards and similar) or try to dissconnect the lock completly (doing the old electronics trick).