Aetrimonde

As I’ve just gone over how skills work, I thought today would be a good opportunity to cover some of the design decisions that went into skill and ability checks.

Typical Skill and Ability Checks

Unlike attacks, where I have benchmarked things so that a typical character will have +4 in the ability they use for most attacks, a character can have a lot of variation in their skill and ability checks:

• Their abilities can range from -2 to +5.
• They may or may not be trained in the skill.
• They also may or may not have a relevant perk in any situation.

I’m going to define a typical ability or skill check as:

• Having +3 (the midpoint of the positive ability modifiers, +1 to +5) in the relevant ability,
• Either being trained or having a relevant perk, but not both. (Granting +2 from expertise at level 0.)
• Not being impeded by encumbrance.

This will give a +5 bonus in a skill at level 0.

Deviations from the Norm

However, this leaves a lot of room for variation: a character with +5 in a relevant ability, or both training and a perk, or that has specialized in a skill, will be significantly better than is typical. This could give a bonus as high as +10 with favor at the high end, although+7 or +5 with favor is probably more usual.

It’s also possible to be significantly worse than is typical, such as by just having a bad ability or lacking training or perks, or being encumbered by armor. This could give bonuses as low as -5, although +2 is probably more usual.

I’m okay with both of these departures from the “typical.” Skills aren’t like attacks, where I want all characters to have broadly similar chances of success when attacking in their preferred method. What I want to accomplish with skills is that all characters have broadly similar chances of success with skills that they are decent at, while retaining variation between characters in the same skill.

That is to say, I want a wizard to be roughly as good at Arcana and Intelligence checks as a rogue is at Subterfuge and Dexterity checks. But I don’t need the wizard to be just as good as the rogue at Subterfuge, and in fact I think it’s better for the game if the rogue is better at Subterfuge than other characters.

Why is this, you ask? When making attacks, characters must succeed on their own merits, and so need to have attack bonuses in a tight range. With skills, it is generally the case that the party succeeds based on the merits of whichever of them is best. (Exceptions exist, like with Deception and Stealth, where one character doing poorly can screw things up for everyone.)

In other words, a typical party should contain a character who is typical (if perhaps not excellent) in most skills. +3 ability, with training or a perk, seems to me to be a pretty good definition of typical here, making it possible for a character to be typical, or close to it, in a wider range of skills.

Typical Difficulties

To achieve the targeted 2/3 odds of success, I would like the typical Difficulty to be about 5 points higher than the typical skill or ability check bonus. That means it should be 15, which is a conveniently round number. But, there should also be unusually easy Difficulties, where even below-average characters can have decent odds of success, and unusually hard Difficulties, where even a decently skilled character may struggle.

I’m going to set Difficulties based on this idea of 15 being typical, with deviations of ±2 being fairly common, and ±5 being more significant. Which is to say, most Difficulties should be between 10 and 20.

Extreme Difficulties

I’m not a fan of the style of GMing that requires a skill check to not choke on your food. Nor do I recommend setting skill checks that are so high as to be virtually impossible for characters to make (especially if they gate off the party’s path forward…).

About the lowest Difficulty that is worth using is 5: this is just high enough that a character bad at the check has a noticeable chance of failing, and I would not bother slowing down play to make a character who is actually good at the check roll.

There is more room for extremely high Difficulties: for instance, I include locks with Difficulty 25 in the list of purchasable equipment. That is a high enough Difficulty that only a very skilled character would have a decent chance to open it in a single attempt, but a decently- skilled character could get it if they work at it long enough. Again, I would try to avoid slowing down play by making a character roll unless there are consequences to failure (like setting off a trap or somehow breaking their tools): instead, if they have ample time and at least +5 Subterfuge, I would simply let them open it after working on it during a rest.

Example Difficulties

To give some examples of difficulties fitting into this paradigm, I shall present some examples from the Athletics, Perception, and Society skills:

Difficulty	Athletics	Perception	Society
10	Climb a rough stone wall.	Hear shouting through a wall.	Find one resident in a small village.
13	Climb a worked stone wall, with the aid of a rope.	…And from 6 meters away.	Find one resident in a welcoming mid-sized town.
15	Climb a worked stone wall.	Eavesdrop on a nearby conversation.	Find a good tavern in a large metropolis.
17	Hold position on a worked stone wall using one hand.	Spot one person in a crowd at 70 meters.	Locate an assassin-for-hire hiding in his tiny, close-knit hometown.
20	Climb in a narrow space between two slabs of glass.	Spot one person in an identifally-dressed crowd.	Find one resident in a large metropolis.