[ZeroSum]

The Biofeedback Filter program states that the effect of this program is to:

Allow Device Rating or Body roll to soak Matrix damage.

The August Errata also states that:

By default, Matrix damage is resisted with Firewall and Biofeedback damage is resisted with Willpower.

How do these interact?

As an example, let's say I am running an Erika Elite (Device Rating 4, Data Processing 2, Firewall 1). How is damage resisted in the following scenarios:

Device Mode.....	Biofeedback Filter.....	Damage Type.....	Resistance Attribute
AR/VR	No	Matrix	Firewall 1
AR/VR	Yes	Matrix	Firewall 1, Device Rating 4, or Body X
AR/VR	NA	Biofeedback	*1
VR	No	Biofeedback	Willpower Y
VR	Yes	Biofeedback	*2

*1 It does not seem possible to be able to inflict Biofeedback damage to a target using AR

*2 Biofeedback Filter seems to apply to "Matrix Damage", but if your attacker is using Biofeedback then the damage code is changed: "Causes Stun (if the target is in cold-sim) or Physical (if the target is in hot-sim) damage with Matrix attack". Somewhat paradoxically, this seems to imply that Biofeedback Filter applies to Matrix damage (such as from a Data Spike or Tarpit), but not biofeedback damage (because you are no longer inflicting Matrix Damage, but Stun or Physical).

Is it just me or is this program awkwardly written?

Defuse is in much the same state; Data Bombs inflict Matrix Damage (and specifically calls out resisting it with Willpower), and having Defuse running allows you to soak that damage with Device Rating or Body. It doesn't say whether this is instead of or in addition to the Willpower soak, but my assumption is that it is instead of or the program would have say something like "allow Device Rating or Body to be added to the soak roll to resist damage from Data Bomb".

[CigarSmoker]

I think RAI is that it helps the Persona resist against the Biofeedback Program (Biofeedback Filter <-> Biofeedback; name similiarity)

But there are other explanations as well.

On p.198 Rigger Programs its mentioned that you might rename a Program. Now you could rename the "Biofeedback Filter" to "Uber-Firewall" and use it on your DR 6 Commlink to roll DR as Firewall. It would still be a "Biofeedback Filter" program just another name.

[ZeroSum]

I'm still really confused by this program.

Take the test decker I built earlier. His Firewall is 9 and his Willpower is 6; if I used the Biofeedback Filter program to resist Matrix damage (normally resisted by Firewall as per the Errata) I could theoretically roll Device Rating 4 of my deck or Body 4 while the program was running.

1. Is this in addition to the existing Firewall roll, or instead of?

2. Similarly, if someone uses Biofeedback or Blackout when they attack me; does the Biofeedback Filter even apply in this case?

The program specifically states that you get to soak "Matrix damage" with Body or Device Rating, but Biofeedback and Blackout change the damage code to Physical or Stun, depending.

And finally, the Errata also mentions that "OS increases by 1 for each Matrix action modified by a hacking program".

3. Am I right to assume that defending against an action is not an action? So I won't gain Overwatch for using Armor, or Biofeedbackfilter, as these are defensive programs and not used in any Action I can think of.

Programs like Biofeedback or Overclock, on the other hand, apply to Actions I take (Data Spike and Tar Pit, and any Matrix Action, respectively).

4. What if I use both programs simultaneously? Since OS only goes up by 1 "for each Matrix action modified by a hacking program", it would seem as if having a Matrix action modified by multiple programs would only count once.

[Banshee]

I'm still really confused by this program.

Take the test decker I built earlier. His Firewall is 9 and his Willpower is 6; if I used the Biofeedback Filter program to resist Matrix damage (normally resisted by Firewall as per the Errata) I could theoretically roll Device Rating 4 of my deck or Body 4 while the program was running.

1. Is this in addition to the existing Firewall roll, or instead of?

2. Similarly, if someone uses Biofeedback or Blackout when they attack me; does the Biofeedback Filter even apply in this case?

The program specifically states that you get to soak "Matrix damage" with Body or Device Rating, but Biofeedback and Blackout change the damage code to Physical or Stun, depending.

And finally, the Errata also mentions that "OS increases by 1 for each Matrix action modified by a hacking program".

3. Am I right to assume that defending against an action is not an action? So I won't gain Overwatch for using Armor, or Biofeedbackfilter, as these are defensive programs and not used in any Action I can think of.

Programs like Biofeedback or Overclock, on the other hand, apply to Actions I take (Data Spike and Tar Pit, and any Matrix Action, respectively).

4. What if I use both programs simultaneously? Since OS only goes up by 1 "for each Matrix action modified by a hacking program", it would seem as if having a Matrix action modified by multiple programs would only count once.

1. Due to changes made along the way that didn't get applied everywhere this is unclear.
Should be additional

2. Yes
3. Yes
4. Yes. +1 per action

[ZeroSum]

Excellent, thank you @Banshee.

Am I right that you actually wrote (large parts, if not all of) the Matrix section? Think I saw a reference to this in another thread. If that's correct, thank you for a) making the rules a lot more streamlined compared to 4th and 5th, b) making the rules more relatable (I could never wrap my head around 5th), and c) for answering our questions on these here forums. Much appreciated!

[Banshee]

Excellent, thank you @Banshee.

Am I right that you actually wrote (large parts, if not all of) the Matrix section? Think I saw a reference to this in another thread. If that's correct, thank you for a) making the rules a lot more streamlined compared to 4th and 5th, b) making the rules more relatable (I could never wrap my head around 5th), and c) for answering our questions on these here forums. Much appreciated!

No problem, and yes I wrote a significant portion of that chapter.  I was also on the development team from day one and worked on the brainstorming of the entire base system just not writing them for final product.

Thanks ... I've been a SR fan for 30 years now so I'm happy to contribute and support it as much as I can.