Capable Familiarity/Proficiency means the character has studied and has rudimentary familiarity with the unique approaches, specific implements (workspaces/tools), or place of the associated Feature (skill or trait). A “Proficiency Bonus” (PB) is the offset of having capability that is familiar and proficient vs. a character lacking these. Familiarity is by a specific frame of reference – group of devices, concept/technology, locale, subject, person, culture (must be an organized, homogeneous culture specific to region, nation, individual, or species if uniform throughout), or process. Experience in some larger context and dynamic situations is required to develop a level of usefulness where common mistakes of misapprehension are no longer made and greater capability can be applied. Contextual elements such as Advantage, Disadvantage, and GM Narration may offset a lack of PB.
i20™ Making Checks: In going with the "Rule of Averages", only a single Result Check is made to determine Success or Failure and degree/quality of either of an Activity. The GM will { } Narrate it, and/or you may petition for an appropriate impact when anything other than a basic outcome is indicated. Note that checks made without proficiency can only apply a Attribute bonus no greater than the character's Proficiency Bonus.
The proficient character can apply their normal d20 Proficiency Bonus of their Character Advancement to their actions if applicable.
The proficiency character ignores non-proficiency penalties to their actions.