This skill allows the character to operate a computer as well as allows the character to write programs or change them to their own specifications. Hacking is also included under this skill, but uses Disable Device, which you must be trained in before you can attempt to hack. Below are the uses for Computer Use. In each case you will use your ranks in Computer Use plus Intelligence to roll to meet the TNs. These are not separate skills.
This use of the skill allows you to program, code, and generally create software for computers. To create a simple application/program requires a TN of 20. This simple program can do a few basic commands. Each extra command/feature added to the program raises the TN by 10. Yes, EVERY command/feature. This is why it takes months, sometimes years, to develop software. On that note, you do get bonuses to your rolls for time. Every week you spend will add 10 to your base roll. So for example, if after adding all the features you want, you are at a TN of 50, you can spend 4 weeks and add 40 to your base roll, so 40 plus your ranks in Computer Use plus your Intelligence modifier. You could also spend 5 weeks and get 50 added to your base total, which almost guarantees a success. In this case, it is possible, but you still need to roll to see if there were any failures along the way. As long as you don’t roll a 1, then it is successful. If you roll a 1, there was a major bug and you have to start from the beginning.
This use of the skill also allows you to diagnose software issues. The Base TN to do so is 25. To resolve the issue is a base TN of 20, plus 10 for every issue found. Again, time will add to your base total, just like above.
This use of the skill covers not only the knowledge of what hardware works best and the latest, fastest available, but installation, troubleshooting, and repair of that hardware. The Base TN to diagnose a problem is 25 (hardware only, does not count networking or software). To resolve the issue is also Base TN 25 plus 5 for every issue found. Taking time, like with Programming, will add to your base total, but instead of 10 for every week, it’s 5 for every hour. Otherwise, rolling rules are the same as with Programming.
This use of the skill allows you to setup and maintain WANs, LANs, and PANs. Essentially, anything to do with connecting 2 or more computers and/or devices together to share information. To create a network from scratch starts at a Base TN 25 plus 5 for every computer you want to add to it. If the number of computers exceeds what you could ever reach with your total dice, then like with Programming, you will gain bonuses to your rolls for time. Every week you spend raises your base total by 10. If you’re willing, you can commit to months and it will raise your total by 50 per month. This is of course, added to your base total as the farther over the TN you are, the less buggy it is in the end.
This use of the skill also allows you to diagnose network issues. The Base TN to do so is 25. To resolve the issue is a base TN of 20, plus 10 for every issues found. Again, time will help you raise the TN, just like above.
This use of the skill only allows you to setup and maintain the software side of networking, so protocols, access, shares, and the like. To physically set up the network requires Craft: Network, this is running the wires and connecting modems, nodes, routers, and the like. However, if you have at least 1 rank in Craft: Network, you gain a +2 circumstance bonus for Computer Use when using it for Networking.
This use of the skill allows you to bypass computer security and tread where you would otherwise be forbidden. You can only use Computer Use to hack if you have Disable Device. And, when Hacking, you will use your ranks and attribute bonus in Disable Device NOT Computer Use. However, instead of using Dex as your main attribute for Disable Device, in its Hacking use, you use Intelligence instead. Additionally, if you have at least 1 rank in Craft: Network, you gain a +2 circumstance bonus to Hack into networks,
Once you have the prerequisites, you can begin to hack. This is treated much like any other Disable Device check in that each computer security system will have a TN. Meet or exceed that TN and you’re in. Now, there may be multiple layers, each getting progressively more difficult. This is up to the GM as well as what you can control in what layer of security.