There is a big ambiguity in the Conan Role-playing Game rules mentioned on the ZeFRS site that the referee will have to resolve before trying to play, which is that modifiers to the die rolls call for shifting the columns to the left or right, but there are two kinds of columns on the resolution chart and apparently no consensus by the fans of the game exactly how they’re used.
Specifically there are small columns corresponding to individual numbers, except at the extreme edges of the chart where they become ranges, and then there are larger groupings of the numbers together into bands of five. It’s pretty clear that when you roll against a particular talent, or attack by subtracting the defenders Move from your Fighting, you’re looking up a particular number in the column… but when you then shift that right 2 or left 1, do you just go to the next number left or right, or the next big band left or right? While shifting number by number is simple and seems obvious, it produces really tiny changes in the die rolls needed for success. E.g. even being completely blind is only a -6 shift, which would take marginal success from, say, 72% to 54% and great (red) success from 10% to 7%. And that’s the largest penalty there is in the reference guide. More typical penalties and bonuses of 1 or 2 columns barely budge the needle. It would have been simpler and completely unambiguous to describe the modifiers as adding or subtracting from the rating itself, instead of shifting columns. Plus interpreting a shift column as a “band” means the dark vertical lines are there for a purpose more than just a visual aid to keep which column you’re looking in straight. In addition when using bands for shifting +/- 6 to an action is actually the largest modifier the chart can support, making it quite natural to say that attacking a bound foe (the biggest bonus) is +6 columns and attacking while blind (the biggest penalty) is -6.
Despite that, I suspect the original intent was probably just shifting the rating up or down, firstly because it would have been really sloppy to write up the rules without discussing the difference between the minor and major divisions on the chart if the major divisions were critical to using it. Secondly, having the shifts be by the minor rating columns allows more leeway for stacking modifiers, such as fighting from a lower position and in the darkness. But since tiny modifiers aren’t worth the mental effort, and I think attacking a helpless foe ought to give you a bigger bonus than a paltry 18%, if I were to play I’d probably choose to interpret column shift to mean the big bands.
If you’re doing that, though, you have one more nicety to address, which is when you shift a band where in the band do you roll? Are you shifting the minimum necessary to fall in the band (closest column to original), the maximum (farthest), smack in the middle, or proportional to your position in the starting band? Personally I’d go with the last interpretation, so that if, say, your rating is 9 (second highest in the 6-10 band) if you shift left by 1 you’d look on column 4 (second highest in the 1-5 band). Similarly, shifting right by 1 from 9 would take you to the 21-25 column (second highest in the rightmost band). That way you keep the relative ordering of the characters: If Anna has Dirk 10 and Beryl has Dirk 9 and they both get a -3 shift for fighting with two weapons, Anna is still better than Beryl (rolling on the -1 column instead of the -2 column).
Doing this tends to make stacking modifiers pretty irrelevant: you hit the limit of the chart pretty quickly. If that bothers you, you could make it so that once you reach the extreme left or right band each additional shift is one column within the band. Since the columns themselves are in groups of 5 that even makes a certain amount of sense, but it does add extra complication. As D&D 5e’s advantage/disadvantage rules show, it can be really liberating to not have to care whether you’ve accounted for every conceivable bonus. In fact, that suggests an alternative way of doing it, which is to ignore the chart of the exact modifiers and count anything that gives you a left shift as one band left, anything that’s a right shift as one band right, and if you have both they cancel regardless of how many are stacked on one side or the other.
Tales of the Rambling Bumblers 