This section describes what happens to a character when the player makes either the best roll possible or the worst. The best success is called a "critical" success, while the most horrendous failure is called a "critical" failure. Either way, these two scenarios can make for darkly humorous or downright grim consequences.
There are two dice that can be considered for critical successes or failures: The twenty sided die, and the percentiles. Both these dice are used extensively in physical combat, spirit combat, saving throws, ability checks, thieving checks, and divine intervention. The table below displays the qualifications for a critical success.
The scores listed are unmodified die rolls. In other words, a roll of 1d20=17 that has a +3 modifier does not count as a critical success. Likewise, neither does rolling a 2 on a 1d20 using a damaged sword (-1 penalty) constitute a critical fumble.
Sometimes, even on a roll of a Critical Success, an event is impossible to occur and should be ruled as such. For example, even if an unskilled adventurer rolls a Critical Success for his attempt to perform brain surgery or to understand a completely unknown artifact or language, the GM should not permit such an event to occur - sometimes, things just cannot happen.
Similarly, Critical Failures should not be used as ways to torment players, especially in circumstances relatively free of stress. If an adventurer attempts to read an ancient language in a cave and rolls a Critical Failure, the GM should not rule something so strange as: “the player feels the rune is an ancient curse and thus he runs away.” Again, such results make no sense and should be discarded.
Note that these tables assume relatively normal combat conditions, thus sometimes the results will not work in a given situation. A GM may: reroll on the table, ignore the result, or create a new result that is appropriate.