Another note: there's no restriction to having only 1 spider....
True that! the previous edition even talked about a "...special kind of rigger, the security spider..." that "...slave their RCC to the buildings host and connect to the entire security system, including all of its slaved drones..." but also that the the "...spider-rigger is often teamed up with a spider-decker to help against hacking intrusions on the security system".
The 'Spider' (as in corporate hacker), using a cyberdeck, protecting the integrity of the host.
The 'Security Spider' (as in corporate rigger), using a RCC slaved to the host, protecting the physical facility.
Both working from inside the same host (= direct connection to all the slaved drones).
Note: Not too big a fan of that last point here, at least in part. I recreates that weird situation from 5th Edition where all host are magical clouds in the Matrix with perfect Noise canceling capabilities. If the host has a kind of physical backbone and isnīt just "everywhere" in the Matrix (and Iīd say that this is the default for most "security" hosts, not the other way around), then it should matter to some degree how far the Patroling Drones steer of the perimeter.
But to my main point: Technically, Spiders donīt need either a Deck or an RCC to protect the host to some degree. As long as they stay inside, they can always use the host attributes for themselfes and lend their Mental Attributes to the hostīs defense Tests. In that regard (and thatīs a key function of Spiders in the new Matrix rules!), thereīs a huge overlap between a "Decker-style" Spider, a "Rigger-style" Spider or even just a "Dude with a Commlink that knows a bit about Matrix security"-Style Spider. Having a RCC, Control Rig, Deck, Cyberjack and/or Resonance just adds more options, physically or in the Matrix. RCCs and Control Riggs helps you to better coordinate Drones to hunt for intruders, while Decks/Jacks/Resonance allow you to leave the host and hunt them down in the Matrix (Which might be necissary quite often, since some hostile Actions donīt require insider Acces).
Which brings me to the question:
Where does a Spider (of any kind) have to "sit" in relation to a host to protect it? Figure a nested host like this:
Outside Matrix ===== A ("lobby") ===== B ("security") ===== C ("root") ===== McGuffin
There may be other hosts nested in this structure, I just fokus on these 3. The "lobby" is easily accessible for outsiders - maybe even without any actual hacking through some entry level social engineering. Then thereīs the "security" host: Thatīs the nest of the Spider, and itīs also where most of the physical security devices are slaved to so that the spider can monitor them. "root" is some ultra-secure insiders-only data host. Thatīs where the runīs McGuffin can be found. Which hosts (and other things, like the McGuffin) can now now actually be considered "protected" by the Spider?
The current Matrix rules are still "malleable" in that regard, so right now, itīs basically "Whatever the GM feels like is working best." As a GM, I have a strong preference here: As long as the Spider sits in host B, he can only buff the protection of Host B and the direct "children" of it. Or, basically, all the Firewalls that he can immediately "see" in the Matrix from his current position - and explicitly
not the whole System.
Why so? Because it makes things more interesting.
Letīs say that our Hacker (marked with an H) has already penetrated the outer layer and infiltrated A. The Hecker also has figured out that thereīs a high-level Spider (marked with an X) sitting in Host B. (Tipp: Picture the nested hosts as 3 nested circles instead, with the Spider sitting in middle layer. The lines of the circles are the Firewalls of the different hosts. The Spider protects just the adjacent firewalls.)
Outside Matrix ==== A ("lobby") ==H== B ("security") ==X== C ("root") ==== McGuffin
That would make hacking B more difficult, but
also hacking into C to retrieve the McGuffin. With that double protection, the Hacker figures that this would be to risky. So, time for a little diversion : The decker calls in a favour from a local Matrix Gang (or compiles a Sprite etc.) to cause some ruckus from the outside: Vandalism, Dataspiking low-priority devices, harassing customers - just enough for the Spider to emerge from B to kick some ass.
Outside Matrix ==X== A ("lobby") ==H== B ("security") ==== C ("root") ==== McGuffin
That would leave B and C more vulnerable, which might be just the
Edge advantage the Hacker needs. Besides that, this handling also creates an ingame explanation on why hosts are not just layers after layers after layers of firewalls to stall hackers. The more layers, the more spiders are needed to protect them all.