Chapter Four: Hacks
Hacks are the province of hackers in True20, who can exchange feats for the ability to acquire and wield various mind tricks.

Hackers acquire hacks like other heroes acquire feats. In fact, a hacker can choose to exchange a feat to learn a hack instead. Also like feats, some hacks have prerequisites that must be met in order to acquire them. A hacker can meet a hack’s prerequisites and acquire it at the same level.

Hack Rank
Hackers have a hack rank that operates much like a skill rank, measuring the overall effectiveness of the hacker’s hacks. A hacker’s hack rank is their hacker level +3, so a 1st-level hacker has hack rank 4. Mixed-role characters use only their hacker level for determining their hack rank; it requires dedication to achieve true mastery of the cyberbrain arts.

Save Difficulty
Hackers also have a Difficulty used when subjects make saving throws against their hacks. The base save difficulty is half the hacker’s level (rounded up), plus 10. So a 1st-level hacker has a hack save Difficulty of 11 (1/2, rounded up to 1 + 10).

Key Ability
Hackers use the Intelligence ability score as the key ability for hacks. A hero’s total hack bonus with any known hack is their hack rank + key ability score. Total save Difficulty is the base save Difficulty + key ability. So a 6th-level hacker with Intelligence +4 has a hack bonus of (6 + 3 + 4) or +13 and a hack save Difficulty of (10 + 3 + 4) or 17.

WHAT ARE HACKS?
In True20, “hack” is a general term for supernatural traits that characters and creatures may possess. 
The key point is that hacks are supernatural abilities not found in the ordinary world, and there are people (hackers) skilled in using them. The Narrator decides exactly which hacks are available and appropriate in any given setting, and some hacks may be restricted solely to Narrator characters.

Dabblers
If you want to create a hero who just “dabbles” in the hacker world, having only one or two specialized hacks, take just a level or two of hacker for your hero for the hacks, but focus primarily on another role. Experts and warriors with just a few levels of hacker can have some interesting surprises up their sleeves.

Using Hacks
There are a wide variety of hacks that characters can weild in True20 games, but they all share certain common rules. Unless stated otherwise (in the hack description, for instance) all hacks follow these guidelines for use.

Action
Wielding hacks is primarily an act of will. Hackers may gesture or speak when using their hacks, but this is not required. An hacker can use hacks with nothing more than intense concentration.
Using a hack takes a particular amount of time, given in the hack’s description. Most hacks require a standard or move action in combat. Others require a full-round action or longer. Hacks are subject to the normal rules regarding actions (see Chapter 6).

Hack Checks
Some hacks call for a check using the bonus of the hack. This is the same as any other type of check: a die roll plus the hack’s bonus against a Difficulty. The check result often determines the effectiveness of the hack. Some hacks do not require checks; they operate automatically.
The hack’s rank or bonus usually determines its effectiveness in these cases.

Taking 10 and Taking 20
An hacker not rushed or under pressure can take 10 on a hack check, unless the hack’s description specifies otherwise. If the check carries no penalty for failure, the hacker can take 20 as well. Taking 20 with a hack check increases the hack’s fatigue save Difficulty by +20 however, since it counts as twenty uses of a fatiguing hack. This is virtually certain to fatigue most hackers. Additional notes on taking 10 and 20 with hacks are included in the specific hack descriptions.

Attack Rolls
Some hacks require an attack roll to affect a target, particularly in the midst of combat. Any ability requiring an attack roll also takes at least a standard action and counts as the hacker’s attack for that round. Hacks requiring attack rolls are subject to the normal combat modifiers and can benefit from feats like Attack Focus.

Saving Throws
Hacks affecting other creatures allow a saving throw to reduce or overcome the hack’s effect.
Hackers can choose to deliberately lower the save Difficulty of a hack by reducing their effective hacker level to as low as 1. This generally makes the hack less effective (also lowering its rank), but makes it easier to resist any fatigue it may cause (see Fatigue later in this section).
Subjects of hacks can choose to forego the saving throw, willingly accepting the hack’s effects. This choice is made before the subject knows what that effect is! Be careful about allowing people to use their hacks on you, unless you know and trust them…

Range
Specific limitations on the range of a hack are noted in its description.
Some hacks transcend space; they can affect targets anywhere. However, using hacks against targets out of sight and unfamiliar to the hacker is difficult, effectively limiting the range of most hacks to somewhat familiar targets or things in the hacker’s line of sight.
If a hack’s description doesn’t specify a range, assume it is line of sight.

Familiarity
An important factor for some hacks is how familiar the subject is to the hacker. In hack descriptions mentioning a familiarity modifier, determine the relationship between the hacker and the target on the Familiarity table and apply the appropriate modifier to the Difficulty of the hack check. For example, using the Cyberbrain Link hack on a somewhat familiar target increases the Difficulty by +15.

Familiarity Difficulty - Definition
Present +0 
A subject visible to the naked eye or in physical or mental contact with the hacker.
Very Familiar +5 
A subject currently seen or sensed through another hack, a close friend or relative, an item made by the hacker or owned and used for at least a year, a place where the hacker spent at least a year’s time.
Familiar +10 
A subject the hacker has been acquainted with for at least three months, a casual friend.
Somewhat Familiar +15 
A subject the hacker has been acquainted with for at least a week, reading someone else’s memory of a familiar subject.
Casually Familiar +20 
A subject the hacker has been acquainted with only briefly, reading someone else’s memory of a somewhat familiar subject.
Slightly Familiar +25 
A subject the hacker has only seen briefly or had described in detail.
Unfamiliar — 
A subject totally unfamiliar and unknown to the hacker and out of the hacker’s line of sight or physical contact. Hacks cannot be used on unfamiliar subjects.

Mental Contact
Some hacks refer to the hacker being in mental contact with the subject.
This involves the use of the Cyberbrain Link hack, allowing the hacker to contact another character’s mind. Subjects in mental contact are considered present to the hacker in terms of familiarity, regardless of the physical distance between them (no increase in Difficulty). Mental contact does not count as line of sight for hacks requiring it.
Hacks that require mental contact also require it to maintain the hack (unless the hack description says otherwise). That means if the hacker loses mental contact with the subject for any reason, the dependent hack stops working as well.

Multiple Subjects
Although it is easiest to use a hack on a single subject at a time, a hacker can affect multiple subjects with the same hack at once: manipulating multiple computers, making mental contact with multiple minds, and so forth. This requires time, skill, and effort to achieve. A character attempting to use a hack on more than one subject at once increases the hack and fatigue check Difficulties by +2 for every additional target. So, affecting three subjects at once is +4 on the hack and fatigue check Difficulties. If the hack does not require a check, then reduce the hack’s saving throw Difficulty by 2 per additional subject. Additionally, the hack requires a full-round action to use. If the hack normally requires a full-round action or more, then it requires an additional full-round action.
The various subjects must all be within range. If the hack requires mental contact, then the user must be in mental contact with all subjects. The Narrator has the final say on whether a hack can affect more than one subject at a time and, if so, how many.
The Widen Hack feat also allows an hacker to affect more than one target with a hack at once.

Fatigue
Some hacks are fatiguing, putting a strain on the hacker’s mind and body. When an hacker uses a fatiguing hack, make a fatigue save.
This is a Will saving throw against Difficulty equal to the hack’s base save Difficulty, or 10 plus half the hacker’s level, rounded up. (Note the hack’s key ability is not added to this Difficulty, unlike the hack’s saving throw Difficulty.) A successful save results in no ill effect on the hacker. A failed save means the hacker suffers a level of fatigue. See Fatigue in Chapter 6. Rapid use of hacks in a short period of time takes a toll on an hacker, and makes it harder and harder to stave off fatigue. Every time an hacker uses a fatiguing hack within an hour’s time, the Difficulty of any successive fatigue save for using hacks (of any type) increases by 1. For example, an hacker uses a fatiguing hack, making a fatigue save against the normal Difficulty. A minute later, the hacker uses another fatiguing hack. This time the Difficulty of the fatigue save is 1 higher.
Use of certain hacks in rapid succession can tire out even the most powerful hackers.
To eliminate the cumulative fatigue save modifier, a hacker must refrain from using any fatiguing hacks for at least an hour. The hacker doesn’t need to physically rest during that time, just avoid any further uses of fatiguing hacks. At the end of the hour, the accumulated penalty is removed.
An hacker can also use the role’s core ability to spend a Conviction point at any time to eliminate the cumulative fatigue save modifier, setting it back to +0.

Maintaining Hacks
Some hacks can be maintained; that is, their effects can continue at the same level achieved by the initial use. This maintenance requires at least a modicum of concentration on the hacker’s part. Maintaining an effect is a free action each round.
Using another hack (or another application of the same hack) while maintaining other hacks increases the Difficulty of the hack check and the fatigue save by +2 (regardless of the total number of hacks maintained).
An hacker distracted while maintaining hacks must make a Concentration check with Difficulty 10 + 2 per maintained hack.
Additional modifiers may apply for damage and other distracting conditions (see the Concentration skill). A failed check means the hacker stops maintaining all the hacks. Keep in mind that hacks requiring mental contact require the hacker to maintain both that and hack the Cyberbrain Link hack at the same time.
A hacker unable to take free actions (due to being stunned, for example) cannot maintain hacks.

Concentration
Some hacks require intense concentration to maintain. The hacker must devote a standard action each round to concentrate and maintain the ability rather than a free action. Concentration checks and Difficulties remain the same as maintenance. You can maintain a concentration hack as a move action rather than a standard action with a Concentration check (Difficulty 10 + hack rank) once per round. A failed check means the hack lapses.