In Source, use of a skill will be represented by roleplaying appropriately for a specific amount of time (the "cycle time"), then Testing for success or failure. Testing is performed by making a blind draw from a bag of stones - white stone means success, red stone means failure. Testing bags and stones will be provided by the Source Campaign. A Testing Bag will begin with 5 white stones and 5 red stones for a level 1 skill. As a skill increases, a white stone is added and a red stone removed. So a level 2 skill Testing bag will contain 6 white stones and 4 red stones and a level 5 Testing bag will contain 9 white stones and 1 red stone.
Some skills have pre-defined general uses (Doctor, First Aid, Hunting/Trapping, Handyman) - uses of these skills are considered Tasks and may be done at will in any appropriate situation. Most skills will have different requirements and/or effects depending on the situation - these will be detailed on a Challenge note, which describes any requirements, limitations, failure consequences, etc. and may also include an envelope to be opened upon success (which may contain additional Challenges). If you find a Challenge note and you meet all the prerequisites, you may attempt it without a GM present (unless the note says otherwise). Otherwise, if you think you should be able to use a skill to do something but there is no Challenge note present, find a GM and ask.
Each Skill or Challenge will generally allow at least one, and possibly more (depending on the specific Skill or Challenge) assistants. Each Skill will have a default maximum of assistants for Tests with that skill, but that may be overridden by a specific Challenge and will be noted in the details of that Challenge. For each task, one character must be designated at the Primary and all assistants are designated as Secondary. Assistants must be present for the entire cycle time of the Test. If the Primary character fails a Test, each assistant may make a substitute Test (with their own bag, at their own Skill level) immediately, and any success will be effective. No character may participate (as Primary or assistant) in more than one Challenge at the same time.
When the Failure Consequences mention Resources are consumed, this means separate Resources must be available and used for *each* attempt. Also, when Resources are required in general (as opposed to equipment), those Resources are assumed to be consumed upon success, unless explicitly noted otherwise - but if there is no failure consequence listed, additional Resources are *not* required for continued tests on the same Task/Challenge.
For each level of the Insightful Advantage purchased, a Character may - once per *game* - immediately Test again after a failed draw. This may be used on a Primary or Secondary Test, or even a failed Insightful draw.
Unless a Task or Challenge defines a specific failure consequence which prevents it, you may continue RPing the Skill and make another test after another increment of the cycle time.
A character with a given Skill who is unable to perform it for some reason (generally injury) but is still conscious may "talk someone else through" a Challenge at a penalty of two Levels. If the Mentor cannot actually see the task (i.e. done over a phone/radio), the penalty is three Levels. In neither case does the Mentor count as an Assistant. Example: Bob, a Doctor 4 has been shot in the chest, and is thus unable to do a CRF treatment on himself. He may supervise and instruct Fred, who may make Tests as if he was a Doctor 2.
Given the time sensitive nature of the Doctor and First Aid skills, Source recommends that characters with these skills set up dedicated testing bags for them, so that there need be no management of a testing bag during, before, or after a test of these skills. While a character's mortal wound counter does pause during CRF treatment (and stops when successful or when First Aid is successful), other people's MWC's may still be ticking down...
Also, yes, we know First Aid only goes up to Level 2, which means the best first-aider only has a 60% of success. Keep in mind, the cycle time on First Aid is only 1 minute, but also, it's a harsh world out there - emergency medicine post-Collapse is not for the faint of heart!
Some challenges will be so complex as to encompass more than one skill test, and/or to *require* one or more assistants. The details for any Challenge of this nature will be revealed at that challenge. Typically, all challenge details will be available at the challenge itself in the form of an explanation document. This is to provide appropriate characters with the details they need to discuss the Challenge in character and to provide out of character details about how to proceed.
Additionally, some challenges will require a minimum Skill level of the skill to have any chance of success. This will be noted on the Challenge itself (as well as the requisite skill levels to qualify assistants, if they differ).
The majority of Challenges and Tests will likely take place outside of the view of GMs and Staff. You may end up making 90% of your tests completely isolated from everyone else. The system is designed to be fair, and the game depends on you being fair as well. The only enforcement we have of any of the rules of this game, including the combat system, is completely based on the integrity and honesty of our players. Please be fair to everyone around you and to the game by abiding by the results of the test.
Almost all of the skills in Source are entirely abstracted. We encourage and hope that players will roleplay the efforts involved in their challenges. We have set the system in this way to minimize the distraction if challenges involved puzzles that had little or nothing to do with the task at hand, and to ensure that character skill (outside of combat) does not vary based on the abilities of the *player*. During the cycle time, do whatever you feel is appropriate given the Skill(s) being used, with whatever props you have (or are provided for a Challenge). Trust us - roleplaying Skill use in this way will be much more fun and immersive for you and others around you than just counting in your head or staring at a watch (or, probably, doing sudoku). That said, every player (with Skills) should carry some sort of timepiece/stopwatch/whatever so they can accurately track cycle times, and you are entirely welcome to do sudoku or whatnot if you think that's close enough to the Skill.