Roll a check when a character attempts an action and its success is in doubt due to fixed or environmental factors, or limited largely by the skill of the character. Most skill rolls are checks; saves are checks; a Strength-based roll to open a stuck door is a check, and so on.

  • On checks you do well by rolling at or below a target number. Bonuses raise the value of the target number, making the roll more likely to succeed, and penalties lower it.
  • The difficulty of a check is reflected by the number of faces on the die to be rolled. So a relatively easy check might be rolled on a d6, while a more difficult one might use a d20.


In contrast, when the action is directly opposed by another character, the roll is a challenge. The most common challenge roll is a to-hit roll against another character’s defense. Note that some competitions between characters may call for a check when the opposition is not direct. For example, in competitions of strength, arm wrestling would be a challenge (one character must defeat the other in order to win, and each is actively working to push the other’s hand back), but a bench-press competition would be a comparison between checks (the contest, for each, is between themselves and the weights).

  • Challenges use 2d101; bonuses are added to the result of the die roll, and penalties are subtracted.
  • Unlike checks, challenges have no additional measure of difficulty, and no target number. Instead, the higher of the two results wins.

Special Rules for Rolls

In general, aside from indicating success or failure, no roll result is more “special” than any other. There are exceptions, of course, noted in their specific contexts. However, players that want a little more risk and reward may use one or more of these optional systems (although not, obviously, at the same time):


A “critical” is a rare but extraordinary result. If the dice produce the best possible result (i.e. a “natural” 1 on a check or a natural 20 on a challenge), it is a critical success. A critical success produces some especially beneficial result. For example, a critical success on a to-hit roll might produce double damage, automatic maximum damage, or a “called shot” that hinders the target in other ways than mere damage. In some cases, a critical success roll may be counted as a success even if, numerically, even the best possible result still would have been a failure.

Similarly, the worst possible result (i.e. the highest possible result on a check, or 2 on a challenge roll) is a critical failure. Naturally, this produces some effect even worse for the character than simple failure; for example, a critically-failed to-hit roll might lead to the character’s weapon being dropped or broken, an accidental injury to the character or an ally, etc. A critical failure may be counted as a failure even if, numerically, the roll would otherwise have succeeded.

Players may suggest critical results as seems appropriate, especially in the case of a success, and doubly especially when it’s an extension of their intended goal from before the roll was made. In all cases, though, the YAM has final say over the exact effects.

High-Stakes Criticals

High-stakes criticals should be played in the same ways as regular ones, but with the “range” extended. This is meant to simulate the character taking a “wild shot” or otherwise overextending themselves a bit in the hopes of a dramatic success. For example, a challenge roll might have its “critical range” extended by 3, so that results of 2 through 5 are all critical failures and 17 through 20 are all critical successes. Obviously, the player needs to declare their desired range before making the roll.

High-stakes criticals should not be allowed if using them would increase the probability of success. (For example, on a skill check of 3 out of d10, the player can’t increase their chance of succeeding from 30% to 50% by using a critical range of 5!) It is not recommended that critical ranges be stretched too far in any case, although the occasional all-or-nothing roll can add excitement to the game.

Degrees of Success and Failure

This is like a more nuanced version of high-stakes criticals, but based on results-after-modifiers rather than on “natural” dice results. First, establish a range. For each multiple of this range by which the roll deviates from the target number, the result is progressively better (for a success) or worse (for a failure) than an ordinary result would have been. Note that challenges tend to have a wider array of possible results than checks, and so should probably have wider ranges for each degree of success or failure.

Below is a chart showing degrees of success and failure, with an example range of five points (the recommended value for use with challenges).

Range Increments Zero (tie)2 One Two Three Four Five
(Example) 0 1-5 6-10 11-15 16-20 21+
Level (N/A) Normal Solid Significant Dramatic Overwhelming

As with criticals, the YAM has the final say in any given result, and determining the exact effects of a given degree of success or failure to everyone’s satisfaction is an inexact art. The best policy is to be consistent; if a solid success on an attack roll gives bonus damage and a significant success gives double damage in one combat, then the same results should probably produce the same effects in later combats as well.


1 Why 2d10? Because multiple dice will offer a curve of results and therefore be less random than, for example, a straight 1d20 roll. This subtly emphasizes the importance of skill over luck. On the other hand, using only two dice preserves enough randomness that the result of any given challenge is not set in stone — and therefore boring.

2 Ties tend to count as a success for the active agent, but in some cases have special rules.


YAOSC (Yet Another Old School Clone) Confanity Confanity