One of the ways to judge what kind of modifier should be applied to a Skill Test in AFF2e is to consider John of Salamonis, an ordinary human with some expertise in the task at hand (effective SKILL 7), and ask how difficult should this task be for him. As described in my last post, he has roughly a 60% of success at an unmodified Skill Test, which accords with the kind of score I usually give to a competent (but not ‘expert’) practitioner in a BRP/d100 game. Which is nice.
But let’s lay it all out in a table:
* In my own games, effective Skill for any task, including combat, is capped at 12. Achieving SKILL + Special Skill scores of greater than 12 allows Adventurers to have better chances of dealing with the kind of heroic level obstacles that impose large negative modifiers.
So, the top line gives us the modifiers that might be imposed on John of Salamonis. The second line gives us his chances of success (vs a target number of 14) as we vary the difficulty of the task. But we don’t need this level of accuracy when we are ‘eyeballing’ task difficulty. So the third line gives us his chances rounded to the nearest 10%, just as I handle BRP/d100 NPCs. As we see, this means that each extra +/-1 modifier can be imagined as adding or subtracting 10% from his chances of success. Which is nice.
Well, except for the jump from 60% to 40%, and that is fine as in my interpretation it represents the difference between an ordinary task being performed under ‘adventuring stress’ with one that has some distinct difficulties. Note that the 100s and 0s in that line represent circumstances in which John of Salamonis will only fail on a fumble (double 1s), or succeed on a critical (double 6s). Again, the actual chances are pretty close to BRP/d100s 5% fumble/critical range. Which is nice.
So when determining modifiers, rather than looking up tables mid play, I try to simply ask, ‘HWWJD?’ How Well Would John Do? If we think our competent everyman would have a 20% chance of success, we should apply a -3 modifier to the task. If we think he would succeed on anything but a fumble (double 1s), we need to give the task a +4 modifier, at least, if we bother rolling at all. And so on. These are applied to the effective SKILL of the Adventurers, which might well be greater (and sometimes, less) than 7.
I advise working out the task difficulties with John of Salamonis in mind, rather than by reference to the Adventurers’ effective SKILL. This is because if I prefer, as much as possible, to have the task difficulty fixed with regard to the fictional world – and John of Salamonis is a fixed point. If I work out task difficulty by considering the chances of Adventurers I do, unfortunately, find myself tempted to fit the world to the Adventurers. If a player has chosen to play a character with a high Sneaking Special Skill, his Adventurer should be able to achieve different things than if that player had instead created an Adventurer with a high Law Special Skill. The task difficulty should be set vs John of Salamonis, not vs Adventurer capabilities. However, the fourth line of the table does provide a guide to the chances of success broken down by effective SKILL (SKILL + Special Skill + modifiers).
(I promise to stop. Well, maybe. Most of these kind of posts are - quite obviously - me talking to myself, laying out the kind of material that I then turn into bullet points, mantras, tables etc. that end up stuck to my 'Referee Screen'. Or the bundle of notes I am using, whatever. It is intended to help me run a game more smoothly and to act as a check against me slipping into the kind of illusionism that negates player choice.)