So...
- mana spells don't work vs vehicles. This includes all health spells. End of. Nice and clear.
- elemental manipulation spells are ranged attacks, can miss, and if they hit are resisted as per rules about vehicles vs normal weapons. Secondary effects are possible, and are worked out based on object resistance and base damage level of the spell as per MITS. Its a *little* ambiguous whether those secondary effects are just "object resistance", rather than it being shorthand for "object resistance unless its a vehicle in which case its 8+bod+half armour". I'd say its probably the latter, making vehicles also pretty resistant vs the secondary effects too.
- any other spell targeting a vehicle uses 8+bod+half armour as the target number, must have a force equal to half that, and the vehicle cannot resist. But what about any secondary effects?
If you take a spell like Blind (which vs organics is *resisted* by Int when cast, contrary to the actual spell description in MITS, you have to look at the table at the end), then the initial casting is clear: get one success and it is blind, full stop can't see anything at all.
Cool, ok, but an organic would then get to make a perception tests as a simple action to be able to see something, albeit with penalties based around the successes on the spell. Does the vehicle get to do this with it's sensor?
Active sensor tests normally take a complex action so its a bit of a moot point - if the drone is stuck making a complex action sensor test each round it is more or less neutralised. But normally a Pilot or Rigger *can* still make a passive 'notice something' check with a free action, so potentially, albeit bumped up to a simple action, could it do this?
Or should such an additional perception test be considered a 'resistance test'? In *that* case, the vehicle can't do that, its sensors don't work, end of.
And what about bind/net?
This targets and is resisted by your quickness, reduces your movement rate by reducing your quickness based on successes. Starts off easy: the vehicle gets no resistance check, the spell works if you hit the target number and have a minimum force.
But by how much is it's "quickness" (speed?) reduced by per success, limited though they will be? Do you just use Speed/10 or something as the quickness score? Do you base it on how the Movement spirit power works where its successes x acceleration? What about the follow on *strength* check to break free of the bonds?
Spells like Chaff get more confusing. It doesn't have any secondary effects, and it already simply targets OR (which again is a bit ambiguous: I assume is shorthand again for "OR for standalone sensors, 8+bod+half armour for vehicle sensors"), and if it succeeds (presumably also requiring the minimum force of half the target number), then it just applies modifiers to the vehicles sensor tests. It has no additional stuff like Blind... but it raises another question:
You can't target vehicle subsystems with spells except for ranged manipulation spells which can take the called shot modifier and outright miss. Subsystems are all part of the vehicle 'aura'. Flak/Chaff are not described as creating sparkly bits of illusiory metal or scrap or what have you, they are described as literally targeting the sensor systems.
So what gives, there?
Confusing... and our players are about to head into Arcology Shutdown, so I really need to know how to handle these potentially 'drone disabling' spells consistently and above all *fairly*.
Help me internet!