No self-respecting cyberpunk game could have a complete lack of hacking. Hacking is works very much on a case-by-case basis, in that each terminal in a scenario has a different purpose, and will be interacted with differently, though with similar ground rules.
Hacking in Orchestra more often than not requires a landline physical connection, or a wireless Local Area Network connection. Either provides enough speed for the actions taking place to work about the same, but it's more difficult to plug into a computer than to beam a signal to it. It is, however, important to remember that almost everything is controlled by a computer, from cars to bank terminals, and security is not always top priority when designing a system. Wireless connections to computers are a convenience, and are near ubiquitous except in military or top-secret facilities, though it often still requires a physical presence on site for security reasons (or due to poor signal quality). That said, many ''secure facilities'' have been compromised by having a hacker open their back door from an alleyway.
Everyone involved in Hacking has a Electronic Systems skill, a Power Rating and a Security Rating. Power comes from a computer, while Security comes from a user's client or imbedded in software (as well as the computer's operating system). Each entity (computer or user) has their own objective. Power Rating determines the number of rolls the user or computer makes with their Electronic skill. Each roll is added until a certain threshold determined by the target's Security Rating is reached.
Hacking is a lot like a normal combat- there can be a lot of combatants. Typically, the combatants will only be on two sides- the intruder's and the defender's, but in specific scenarios it can be more complicated, typically as a result of multiple intruders with different agendas. In all cases, however, each side has a ''primary'' entity, typically the one with the highest Security Rating. Hackers can even bring in programs to do specific tasks that will eat at least a portion their own hardware's Power Rating, but effectively add a second (highly-specialized) hacker to their side.
It is important to remember during hacking that there are multiple computers involved- those of intruder(s) and those of the defender(s). Each has its own Power Rating (typically higher for the defender). Also, not every intruder has to be against the defender. It's possible for a do-gooder to try to defend a system that's under attack by a malicious entity, or for a vengeful hacker to crash a rival's computer in the middle of a high-stakes hack. Each user has a “host computer” (the primary computer he uses), which he can use resources from equally with other users using the same host computer. Should his host computer be dominated, a user loses half his Power Rating.
Hacking has one goal: Domination. A hacker who achieves Domination is capable of undertaking a variety of actions, usually determined individually based on the system they're attempting to enter. Domination requires a threshold equal to 5 times the system's primary defender's Security Rating. Domination doesn't have to be maintained, but it's used to do a number of actions that are otherwise forbidden, and controls access to file management. Domination grants 50% of a computer's Power Rating to whomever controls it for use in their own purposes (the remainder is reserved for legitimate users using traditional interfaces), so it can be a powerful boon. Domination can even be attempted on a remote computer, but it is lost when the hacker disconnects (allowing return of control to the original owner, but this takes a turn to physically accomplish).
Other than Domination, there's a handful of actions to take when hacking. A user with Domination of a system can Crash a user on their own host computer. A crash typically takes three turns to recover from, though some high-end systems restore a user quicker. Domination is also required to use the File commands, such as Delete, Move, Execute, Copy, and Implant, which may be necessary for a mission. Domination also allows usage of Identify, which looks at I/O ports to determine what's hooked up to the system and how to use it, or whether a unknown file is something of value. Once Identify is used, I/O ports may be controlled with a Control task, often allowing control of things like lighting or doors, which can be a major boon to an infiltrator.
Crashing a user is an annoyance, but requires a little work even on a dominated system. To Crash a user, the product of their Security Rating (the system's security rating plus the user client's security rating) and the computer's Power Rating (after adjustments for other users or programs) is required. When the user is crashed, the power allotted to them is reserved for their use, but they are incapable of taking action.
File commands usually take about 3 times the Security Rating of the system to complete, Identify takes about 2 times the Security Rating, and Control takes a different amount based on how important the object being controlled is- turning on and off lights would take about a full Security Rating, while breaching containment at a nuclear reactor would potentially require a chain of complex actions that have no less than ten times the Security Rating of their host system. The average for something that should be done only by an authorized user (like, for instance, triggering a full security alert) is five times the system's Security Rating (ignoring that of software or users).
Progress towards a hacking action accumulates only for that action, and only one action may be attempted each turn (that is, a hacker could put all his rolls towards Domination, but could not split off to do Identification on a system he already dominated). Attempting multiple of the same action (multiple Delete or Identify actions, for example) can be put in the same pool, with the downside of all the actions completing at once (though with slightly more efficiency).
Networking and Multiple Users:
Should a system be accessed which serves as a host for many users, each user consumes at least one point of Power Rating, regardless if they're attempting to hack (or counter-hack) or if they're just looking up pictures of kittens off the internet. Computers meant for only one user (portable computers, for example) don't lose power for their first user.
Similarly, networks are important: many devices can be hooked together. A common tactic for hackers is to grab a ton of phones and route them to a central computer, providing a cluster of low power devices. This doesn't help him defend his main computer (it can be crashed).
Mark needs to get a door open in a corporate enclave. He plugs into the door terminal with his own computer. His Power Rating is 4, while the door terminal's is 2. The door terminal is effectively a passive audience, without any active security programs or users monitoring it, so it takes no actions (but if a legitimate user were to use it he could utilize its power). Mark checks the terminal's Security Rating to find that it has a laughable six. He rolls his Electronic Systems test four times to try to dominate the terminal. Since he has two specializations (one in Electronic Systems and one in Blue), he rolls two dice for each. He gets 7, 8, 2, and 3 as the final roll results, bringing him to a total of 20. If combat were running, a round of that would elapse before he could hack again. He rolls the next turn, getting 8, 7, 7, and 10, so he has Dominated the door terminal. He gains one point of Power Rating from the door terminal, and can attempt sensitive actions, namely Identification of the I/O ports. He now rolls 5 tests, and since the door has 3 I/O ports, he decides to try them all. He rolls a 4, a 8, a 5, a 10, and a 7. Each of the ports requires 18 points to identify, and he came up with a total of 34 points, meaning he's still short, and since he's treating them as a pool, he hasn't identified anything yet. He rolls again to get to the 54, getting 7, 10, and 11 (he stops rolling for expediency). He's identified the ports, and finds out that one is an alarm, one controls the external light, and one handles the actual opening of the door. The door's opened with a simple Control action against the Security Rating, so Mark can't fail, though he does have to wait for the next turn. When he enters, he loses connection to the door terminal, and is back to his original 4 Power Rating, since it's no longer feeding him its power.
Mark encounters a mainframe, and plugs his computer into one of the ports. As he connects, he sees that there's about 20 users on. While the Mainframe has a Power Rating of about 30, the users on the system (presumably making spreadsheets) each consume 1 power rating, leaving it with 10 power for counter-hackers to utilize. Mark's heavily outgunned, so he disconnects before he's noticed. He grabs his phone, and slaves it to his computer (which takes a turn). He now has a joint Power Rating of 5. He plugs back in, hoping his additional power will be sufficient to let him do at least something on the mainframe.
Jane, the security manager for the mainframe, noticed him the first time, but shrugged it off as a legitimate user connecting his own device. This time she knows Mark's up to something fishy, because he goes to try to Dominate the mainframe, despite its Security Rating of 20. Jane tries to Dominate his computer in turn. Mark's computer is advertised to hackers, but it's still a portable computer. Its security rating is an impressive 8, so Jane needs 40 to Dominate the rig, and another 32 (4x8) to Crash him. Jane's a fully trained expert, and she rolls 3 dice 10 times because of her full specialization in the Electronic Systems tree. She is able to dominate Mark's computer easily.
Mark discovers that his computer's been dominated when his combined Power Rating drops to 3 and his computer starts popping up warnings and errors. He keeps pushing, though, because he's compromised and if he doesn't shut down the mainframe Jane can raise an alarm.
Jane crashes Mark the next round, and activates a building-wide alert (as a legitimate user, she knows what the I/O functions are, and she can use them without having to take special actions). Mark wishes he'd brought along some hired guns.