TFL/Combat Hacking House Rules

Computer hackers have libraries of prepared exploits that they can deploy in combat time to have minor effects on computers. Hackers need to adjust the exploits in real-time and while a hacker can work remotely, it becomes much more difficult. Targets of a hacker may choose to drop off their wireless connections to avoid a hacker, but this can limit their effectiveness.

## Basic Terms

Breach
An unauthorized hacker can breach a LAN's security to allow him to run commands on computers on the LAN. A breach is a fragile toehold on the LAN, and the LAN's network defender may attempt to remove the breach.
Exploit
Computers are vulnerable to all kinds of nasty little tricks that impair operation, collective known as exploits. Exploits degrade the efficiency of computer operations, but computers can counter exploits very rapidly.
Local Area Network (LAN)
A group of computers linked to each other by wireless or cable connections, and sharing enough access that a single network defender can provide security for all computers on the LAN. Computers on a LAN share data among each other, but do not intentionally share data to computers outside the LAN.
The minimum useful size of a LAN is all of the computers on all the equipment that a single person is carrying, but multiple people may be in a LAN. LANs do not require line of sight among members.
The maximum distance that two members of LAN can be separated by is the range of their personal radios. LAN members can be connected over a WAN as long as their radios have range to the WAN. No matter what, two members of LAN cannot be separated by more than 46,000 miles.
Network Defender
An entity tasked with resisting breaching attempts and hacking exploits for all members of a LAN. At a minimum, this is a collective effort of all the NAIs running on the computers in the LAN, but ideally an SAI or organic intelligence acts as a network defender. The default network defender is an NAI with effective Computer Hacking-9 and Electronics Op (EW)-9.
A LAN can only have a single network defender at a time, and the network defense activities of all other AIs on the LAN are assumed to be coordinated by the network defender.
Wide Area Network (WAN)
A group of computers linked to each by wireless or cable connections that do not share access with each other. Breach attempts and hacking exploits can be transmitted over a WAN between two computers that are not in line of sight of each other without breaching any computers on the WAN.
A WAN is assumed to exist on any space station or technologically sophisticated planet. WANs do not exist in the vacuum of space or on primitive planets. Spacecraft do not have WANs but have internal LANs for authorized users and hackers who breach the LAN.
## Combat Hacking

### Defining LANs

Every person with a computer on any piece of equipment, or any AI, needs to decide what LAN they are on. Joining or leaving a friendly LAN is a free action taken at the start of each person's turn. People on the same LAN can share tactical targeting data, VR and AR sessions, and silent communication with each other and cannot share that information with anyone who is not on the same LAM.

### Getting In

It takes a Concentrate maneuver and a Computer Hacking roll for a hostile hacker to breach a target's defenses and establish access to the wireless link for the target's LAN. This roll is penalized by 1/3 of the effective Computer Hacking skill of the network defender on the target's LAN. A successful breach grants the hostile hacker access to everyone on the LAN, though individual targets may choose to drop off the LAN. The original target of the breach attempt may not drop off the breached LAN, though they may choose to disconnect from the wider LAN.

### Running Exploits

It takes a Concentrate maneuver and a Computer Hacking roll to exploit a breached wireless LAN. An exploit gives a penalty of 1+MoS/2 to a single target's active rolls (but not defenses or resistance rolls) until the end of their next turn. This roll is penalized by 1/3 of the effective Computer Hacking skill of the network defender on the target's LAN. There is a +1 bonus for every successful exploit run on this LAN in the last 5 seconds and a -1 penalty for every exploit that failed in the last 5 seconds. Success by 5 or more makes the target roll Will to avoid mental stun; a critical success or success by 10 or more automatically mentally stuns the target.

Exploits have to be run on each target in a LAN individually.

Exploiting AI
Any AI is somewhat more vulnerable to hacking attempts than an organic; an AI that is operating a self-propelled shell can be usefully exploited. A hacker that manages to stun an AI in a shell can instead choose to briefly take control of the AI. The hacker can issue a 1 or 2 sentence, non-conditional command that the hacked AI must obey on its next turn. At the end of the turn, the AI resists control with a Quick Contest of the AI's Will versus the hacker's effective Computer Hacking Skill. The AI gets a cumulative +1 for each second after the first that it is under control of the hacker.

Maintaining control of an exploited AI takes no actions or maneuvers from the hacker. It requires a Concentrate maneuver to issue a new command to all controlled AIs on a LAN; individual LAIs can be excluded from the command at the hacker's discretion.

### Multiple Attackers

Two or more hackers may attack the same LAN. If the hackers share a LAN, only one of them needs to breach before the others may attempt to run exploits.

### Playing Defense

On their turn, the network defender may make a Concentrate maneuver and roll a Quick Contest of Computer Hacking against opposing hackers to remove them from a breached LAN, or to remove the penalties for running exploits against all targets on the LAN. Roll a separate Quick Contest for each hacker on the breach and each victim of an exploit.

### Counter Attacks

Breaching a LAN, in some ways, adds the hacker's computer to the LAN. Anyone on a breached LAN gets a +2 skill bonus to breach (but not to run exploits) on the breacher's LAN.

### Signal Jamming

Anyone with a deceptive radar jammer (UT p 99) can use it to influence combat hacking in either of two ways:

1. As a Ready action, the radar jammer can be used to broadcast white noise within a sphere up to 10 miles in radius. Roll a quick contest of the jammer operator's Electronic Ops (EW) versus the network defender's Electronic Ops (EW) skill for every LAN in the radius. If the jammer is successful, everyone connected wireless to the LAN has to drop off all wireless LANs immediately and cannot reconnect for 1+MoS minutes. On failure, the jammer cannot be used again for MoS seconds.
2. As a Concentrate maneuver, the radar jammer can be used to narrowcast white noise at a particular person that is in line of sight of the jammer operator. Roll a quick contest of the jammer operator's Electronic Ops (EW) versus the Electronic Ops (EW) skill of the target's network defender. If the jammer is successful, the target drops off any wireless LAN immediately, which clears an breaches and cancels any hacker exploits that the target is inflicting. The target cannot attempt to reconnect to any wireless LANs for 1+MoS seconds. On failure, nothing happens.

### Going Remote

All combat Computer Hacking skills take long-distance penalties for the distance between the hacker and target. If the hacker doesn't have direct line-of-sight but is sending signals remotely over a WAN, there's an additional -3 penalty. Remote network defenders do suffer these penalties when playing defense and for their effective Computer Hacking skill when providing the static penalty to getting in and running exploits. The default network defender AI is always considered to be at range 0 and in line-of-sight of the LAN it is defending.

### Dropping Out

Hackers can only affect targets with active wireless links. Mundane animals, people without implant computers or computer vision aids, and people who choose to use cable jacks to connect to all their equipment without joining a wireless LAN are immune to hackers.

It is a free action at the start of each character's turn to join or leave a LAN. It is not possible for any member of a LAN with multiple members in it to leave the LAN while any member of the LAN is suffering penalties from a hacker exploit except by turning off all wireless activity and disconnecting from all computers; the person suffering penalties from the hacker exploit can't even do that.

Modern ranged weapons are assumed to be on a wireless LAN projecting targeting data to the wielder's HUD for a +1 on attack rolls. Wielders who completely drop off the LAN lose this bonus unless they connect their weapon to their HUD via interface cables.

Going Wired
It takes 2 Ready maneuvers to connect a device held in a hand to a wired LAN via interface cables. Additional Ready maneuvers may be required to connect a device in other locations. Interface cables can be up to 5 yards long, and in theory multiple individuals can daisy chain through interface cables, but practically this is almost never done. Wired LANs cannot be breeched or subjected to hacker exploits unless the hacker is part of the wired LAN or a device on the wired LAN is also connected to another device on the LAN wirelessly.

People with multiple wired connections may suffer a -1 DX penalty at the GM's discretion. People connected to each other via interface cables may suffer additional DX penalties, depending on the situation.

In most places on the Fringe, walking around with an interface cable visibly connected to a weapon is considered to be brandishing the weapon. There may be exceptions for military, policy, or authorized security forces.