CORE RPG RULES
Iconoclast -- RPG -- Tier Selection
Deciding what tier of skill you're using is mostly a matter of common sense, but it is a vital step in making skill rolls. We're not going to go into all sorts of detail because it is really self-evident, but here a few examples:
Ex.1: Rahl is driving an Indy Car. He looks at his driving skill:
\_Ground Vehicle, 4-Wheeled(MA):20
Since he is driving an Indy Car, which he has specific knowledge of, he
is performing a skill check at the specific tier level. This means that
he adds all the numbers leading up to that tier. Thus, 10+20+25=55.
Ex.2: Rahl is driving a dump truck. Since he is driving a truck, and he
does not know how to drive trucks, his skill is entirely dependent on
his broad knowledge of all things vehicular--his Broad tier. Thus, when
driving the dump truck, he only adds 25 when he's performing his skill
There may be times when you can't find any particular skill tier to get the job done. You may need to lift a big fnorking boulder, but there just doesn't seem to be a "Lift Big Fnorking Boulder" skill anywhere, and none of the other ones seem to fit. In cases like this, generate a target based on the appropriate raw Attribute, plus or minus any modifiers. Then you roll against that Target. Obviously, this generates a much smaller chance of success, but if you don't have the skill to be doing something, then you probably shouldn't try it unless it's really important that you do.