Building a Computer
Source GM Core pg. 223
Every hacker needs a computer to hack! The form a computer takes can vary greatly, from a secure technological database accessed via a holographic interface to an interdimensional tree that grows across realities and stores its data inside colorful, intangible fruits accessible only through lucid dreaming. While incredibly different and bound to sport unique vulnerabilities and countermeasures, both are computers for the purpose of the hacking subsystem.
Concept
Source GM Core pg. 223
The first step to building a computer is to develop an initial concept. What does accessing the computer allow your players to accomplish? What level is it? Is it simple or complex? Is it magical, technological, or hybrid? Does it have a virtual intelligence, or is it a living creature? Does it use remote access points, or does it require direct physical access? You should brainstorm the computer's name and description, as that can help you plan its vulnerabilities and countermeasures.
Computer Types
Source GM Core pg. 223
Most computers have the tech trait and can be hacked using skills like Computers, Crafting, and Thievery. Magic computers might incorporate programmable aeon stones or bound machine spirits that command ancient constructs and are usually Hacked using Arcana, Nature, Occultism, or Religion. Hybrid computers have the tech and magic traits, such as a password-protected spell chip or an arcane barrier controlled by a console. Hybrid computers often have different access points for their magical and technological components, but Hacking either should grant access to the computer. A computer's stat block will never be able to list every possible skill a character might use during a hacking encounter. You can use the values listed in a computer's stat block as a guideline to resolve creative, unlisted solutions to a hacking encounter.
Setting the Statistics
Source GM Core pg. 223
Use a hazard's Stealth and Disable DCs to determine the computer's DCs. Successfully exploiting vulnerabilities with a low DC should reduce the DC to Hack by 1, those with a high DC should reduce it by 2, and those with an elite DC by 3. Penalties to the Hacking DC incurred while exploiting a vulnerability are cumulative and should never be enough to reduce the DC below the low DC. The DC to notice a countermeasure is usually lower than the DC to disable it, which is always high or elite.
Simplified Quick Hacking
Source GM Core pg. 223
For a simplified quick hacking encounter, you can ask each of your players to roll appropriate skill checks to support the character(s) attempting the Hacking check. Each successful skill check lowers the Hacking DC by 1, or 2 on a critical success; a critical failure raises the Hacking DC by 1 instead.
Computer Stat Blocks
Source GM Core pg. 223
A computer's stat block is only necessary when hacking the computer is the primary obstacle. As many vulnerabilities and access points can take several minutes to bypass, consider using a single access point with no vulnerabilities or additional success benefits if your players are Hacking during an encounter. You can use this simplified method to allow players to Hack a basic computer with a complete stat block to perform simple commands, such as unlocking a door, but doing so shouldn't award XP or additional success benefits, and an additional check should be required for each subsequent command.
This provides information about the computer and its purpose.
Access Point Each access point should be noted as physical (if it requires the character to be physically adjacent) or remote (if it can be accessed from a distance). This is followed by the number of successes required to Hack the access point. The DC of skill checks that can be attempted to use the access point are listed here, followed by the minimum proficiency rank required for the skills (if any) in parentheses. Each access point is associated with its own unique vulnerabilities and countermeasures. If a computer has multiple access points, these access points (and their associated vulnerabilities and countermeasures) are listed separately.
Vulnerabilities Each vulnerability lists in parentheses the DC of any skill checks that can be attempted to exploit it, followed by a value of how much it lowers the access point's DC. Some computers don't have this entry.
Countermeasures Lists the nature of the countermeasures that trigger after reaching the number of failures in the parentheses; the DC of any skill checks required to notice and disable the countermeasures are also here. Some countermeasures have the persistent trait, meaning once they've been triggered, they automatically trigger again at the end of each ensuing round. Persistent countermeasures can be disabled even after they've been triggered, and doing so prevents them from triggering again (but doesn't erase the effects of previous triggers).
Computer's Name Computer Level
TraitsThis provides information about the computer and its purpose.
Access Point Each access point should be noted as physical (if it requires the character to be physically adjacent) or remote (if it can be accessed from a distance). This is followed by the number of successes required to Hack the access point. The DC of skill checks that can be attempted to use the access point are listed here, followed by the minimum proficiency rank required for the skills (if any) in parentheses. Each access point is associated with its own unique vulnerabilities and countermeasures. If a computer has multiple access points, these access points (and their associated vulnerabilities and countermeasures) are listed separately.
Vulnerabilities Each vulnerability lists in parentheses the DC of any skill checks that can be attempted to exploit it, followed by a value of how much it lowers the access point's DC. Some computers don't have this entry.
Countermeasures Lists the nature of the countermeasures that trigger after reaching the number of failures in the parentheses; the DC of any skill checks required to notice and disable the countermeasures are also here. Some countermeasures have the persistent trait, meaning once they've been triggered, they automatically trigger again at the end of each ensuing round. Persistent countermeasures can be disabled even after they've been triggered, and doing so prevents them from triggering again (but doesn't erase the effects of previous triggers).
Critical SuccessThis additional bonus is earned if a character achieves a number of successes equal to two times more than is necessary to Hack an access point, or if more than one access point is successfully Hacked. While this is most common for access points that only require one success, it can also happen when multiple characters attempt to Hack a computer at the same time. Some computers don't have this entry.
SuccessThe basic computer functions and benefits available when the characters successfully Hack this computer.