- Referee Fiat
- Ability Score Based Roll
- Level Based Roll
Referee fiat means the ref arbitrarily assigns a chance of success and the player rolls the dice. An ability score roll requires the player to roll under an ability score, typically on 3d6 or d20. For example, he may have to roll his Strength or less on d20 to perform a feat of physical prowess. A level based roll is based upon the player-character's level in some way, such as the Thief ability scores from Greyhawk.
We ourselves have pondered the nature of ability versus level based challenges since an excellent article incorporating player level into the outcome of Chainmail's jousting system appeared in the pages of the Dragon magazine.
First, a quick word about how dice rolls work. This is only basic information so if one is a probabilities wonk please do not get stuck on the simplified language.
Linear versus Weighted DistributionA linear distribution assigns an equal chance of any result. The OD&D monster level tables in Volume III pp. 10-11 are a good example of a linear distribution. They are generated with a straight die roll, that is, if one has 10 possibilities then a ten-sided die is rolled and giving an equal chance of any result in the table.
A weighted distribution is the dreaded bell curve from school days. Weighted distributions have a higher likelihood, on average, of producing a typical result than an extreme result. Take your travel time to and from work: on most days your commute will take an average amount of time, say 20 minutes give or take for the sake of the example. On a summer holiday weekend your commute may stretch out to 35 minutes as you fight hordes of vacationers on the road, whereas on Christmas morning when the whole world is opening presents your may make it to work in 12 minutes. So if you were dicing for that result you would want the most common result to be 20 or thereabouts, to reflect your typical day. The ability score generation 3d6 dice rolls are good examples of this, forcing abilities such as Strength or Intelligence toward average but with a chance for higher or lower results. These chances decrease as you go toward the extreme results of 3 or 18. Weighted distributions are generated by rolling multiple dice and summing the result.
Ability versus LevelSo the reflexive argument for options #2 vs #3 above is the former does not take PC level into account whereas #3 does not take ability into account. Could a young boxer with a great deal of talent (ability score) kayo an experienced but less talented boxer (levels)?
At any rate, a common solution to skill checks typically involves rolling dice on a weighted distribution based upon 2d6 or 3d6. The former is often based around the OD&D reaction table (found on OD&D Volume I page 12) and the latter based upon ability scores.
We propose using the latter: 3d6 for generating a weighted curve of results ranging from 3 to 18. These would be based upon the most pertinent ability score. To solve the dilemma of level versus ability? One could simply modify the sum of the die rolls by +1 per 3 levels, as inspired by Attack Matrix 1: Men Attacking (Volume I, p. 19). This could be further modified in the same way the combat matrix by reducing the bonus to every four levels if the referee feels level is of decreased importance, and by 1 per five levels if level is only minimally important.
In this way experience could compensate for lack of natural ability and increase desired outcomes. The more experienced the PC? The greater the likelihood of a good result.
The table can also be used for random "reaction table" type die rolls but with 3 dice instead of 2. One such proposal is included here. Roll 3d6 on the table below. Give a bonus of +1 per 3 levels (alternately, per every 4 or 5 levels). Results of 7 or higher may be reattempted. Astute readers will note results are weighted toward neutrality, with experience increasing chances for success.
This table may also be used if the referee determines a player must be of minimal level to attempt something. In such a scenario he may subtract -1 per 3 levels (or any part thereof) below the target level from the sum of 3d6.