Step 1: Preparing for the run
The first thing you need is a cyberterminal and some programs. If you miss one or both, you will not reach very far.
When you turn on the terminal and prepare to surf the net, the first thing you'll find is a virtual room off your own terminal. Here you can run your programs locally and specify the name/appearance you'll have once you're inside the net.
Step 2: Traveling on the global network
If you are already connected directly to the target network, you can skip this step.
To travel around the world you have to go through a number of main nodes/proxies. Those are usually in major cities and are often in freely available public lists. However, each node keeps track of your path through the network to inform any tracking program where you come from.
If you want to avoid leaving a trace around the net (that correspond with your real world position, remember I-G algorithms) you have to bypass their security protocols. It's not a very difficult thing to do, but as you reroute signals and stack fake IDs, it slows down your connection.
Each node has a value of "trace" and one of "security" (as always). The former adds to the difficulty of tracking you, the sum of the second divided by two is a penalty of your initiative rolls.
Ex .: If you pass by Night City, Los Angeles, Mexico City, Panama City and City of Bogotá, you'll have a trace value of 13 and a -4 penalty to initiative (7 divided by 2).
Step 3: Infiltration
Once you've reached your goal, you must get into the data fortress and execute your malware ... of which there are plenty.
While you're out of it inoffensively, the system will ignore you. But the moment you start an attack, the system will defend against you (or will send the sysop a notice of your presence). It will be time to throw initiatives and move by turns ... you'll better have Stealth programs to hide or you will understand why runners fear black ice.
Typical checks on the net are:
|Initiative: REF + speed + 1d10 terminal.|
|Stealth and evasion: 1d10 + prog. STR||Difficulty: 6 + Detection prog. STR.|
|Anti-system attacks: 1d10 + prog. STR||Difficulty: 6 + Data Wall or Code Gate STR.|
|Anti-personnel attacks: 1d10 + prog. STR + INT + Interface.||Difficulty: 6 + prog. STR + INT + Interface.|
|Anti-software attacks: 1d10 + prog. STR + INT + Interface.||Difficulty: 6 + prog. STR + INT + Interface.|
|Drivers and utilities: 1d10 + prog. STR||Difficulty: 6 + Data Wall STR.|
The STR refers to the strength of the attacking or defending program. If for example you want to hide, you'll need to use programs to mask your signal or hide your ID and beat the system detection programs (like the Dog series).
If the opponent (either an AI or sysop) is aware of your presence, it can attack you freely. If not it will have to locate you first even if your are running mayhem in their system ... or in a desperate act, they can cut external communications or reboot the system.
To be able to FIND, READ, EDIT, COPY and DELETE data from a data fortress, you first have to overcome their defenses (Data Walls or Code Gates) with appropriate anti-system programs (such as Drill). If you leave the fort and the administrator becomes aware of the security breach, they will be restored.
Step 4: Exit
Once you've finished with your work, you just have to leave to other areas of the net or disconnect (with a roll of 8 or more with a d10).
If you have broken through a data fortress Data Walls or Code Gates, you do not need a test to control remote computer (but you still need the program!).
Without programs you cannot manipulate the net, but you can still browse it, manually interact with Code Gates and access unprotected memory blocks. If you know someone you my try to acquire programs from them or reach Netrunner hubs in the search of a kind soul.
Also, keep in mind that most of Datafortress have public zones where it is not necessary to make a raid to access it. In them you can typically find all kinds of contact information, products or organize meetings.