Let's Talk About Core Game Mechanics

[Scott Christian]

Speaking of mechanics, a long time ago we greatly enjoyed the MERP systems style of combat. It was D100, but you could take your skill and subtract a portion of it to modify any attacks against you. For example, if I had a 55% in one handed weapons, I could just use 33% of it to add to my roll. The other 22% would be subtracted from my opponent's roll. I am not sure I would like it now, but we enjoyed it at that time in our lives.

 

[500 Toads]

Opposed rolls are probably more common than direct subtraction -- whether in terms of comparing degree of success such as how BRP-family systems tend to do it, or net successes in various die pool games such as Shadowrun -- but the current Runequest does use a skill subtraction method in a very particular scenario, where somebody who manages a weapon skill greater than 100% results in subtracting the excess from both his and his enemy's effective skills, making it that much harder for his opponent to attack or parry him. That system does get a bit fancy with >100% skills also enabling one to split the skill rating to make multiple attacks within the same round, too.

 

[Thomas Shey]

I'd argue that to the extent that is true, it's not at the resolution of the delta between linear and normal.

Maybe not, but again, something has to convey the degree of edge one (or one's opponent) has in a combat exchange, and that's one of the functions numbers convey.

 

[Thomas Shey]

Skill 80 = 80% doesn't take into account the difficulty (or armor class) of the challenge, nor situational modifiers. And personally I don't like RPGs that ignore those things.

Most percentile systems don't ignore those things (though baking in armor penetration into the to-hit is largely a conceit of D&D descended games) but the final result is still a percentage.

As I said above, I doubt even very educated guesses are at finer resolution than the difference between linear and normal distributions.

Eh. May still be a case that the actual differential is more pronounced, because things like 3D6 resolution don't feel the need to make sure that the failure chance is potentially high the way it seems like at least D20 based games do (probably in part because most of them as I mentioned don't feel a need to bake armor penetration into that roll).

 

[Thomas Shey]

Opposed rolls are probably more common than direct subtraction -- whether in terms of comparing degree of success such as how BRP-family systems tend to do it, or net successes in various die pool games such as Shadowrun -- but the current Runequest does use a skill subtraction method in a very particular scenario, where somebody who manages a weapon skill greater than 100% results in subtracting the excess from both his and his enemy's effective skills, making it that much harder for his opponent to attack or parry him. That system does get a bit fancy with >100% skills also enabling one to split the skill rating to make multiple attacks within the same round, too.

A functional but kind of klunky way to represent a way for post 100% skills to have function besides increased special and critical results.

 

[MichaelSomething]

This question underscores your position that there isn't a difference, so I am not sure there is much I can say to change your mind.

A "core mechanic" is the system by which the questions that come up in the procedure of play are answered. Does that work for you?

This calls for a fork!

Thread 'Let's talk Procedure of Play'

Today at 5:04 AM

Let's talk procedure(s) of play! What procedures do you like to use??? Which ones do you hate???

• MichaelSomething
• Replies: 3
• Forum: *TTRPGs General

 

[Bill Zebub]

Most percentile systems don't ignore those things (though baking in armor penetration into the to-hit is largely a conceit of D&D descended games) but the final result is still a percentage.

I only meant that the claim Skill 80 = 80%, how easy to understand is that? is either from a system that doesn't take those modifiying factors into account...which seems overly simplistic/boring...or it does take them into account in which case the final percentage isn't 80% and it's not so easy to understand after all.

 

[Staffan]

I don't think linear systems are any more prone to over-relying on random chance than non-linear ones - if you're using a random generator, you're using a random generator. Whether they produce a lot of failed results or not (or crits, fumbles, or successes) depends on the target numbers being set, not the fact that a random generator is involved.

Sure, you could make a game where the skill values overpower the RNG in most cases. Just taking some numbers off the top of my head, you could have a system where a novice has a skill value of like 10, a master has 50, and you roll d10+skill to see if you succeed. Maybe even an exploding d10 to reflect that you might accidentally luck into doing the right thing. This would provide a fairly narrow window of difficulties where random chance determines if you succeed or not, but in most cases you'd know ahead of time if you're good enough.

Bell curves accomplish a watered down version of this. Let's say we're playing GURPS (3d6, roll under or equal to skill) and you have skill 13 and I have 15. On a normal task, your chance is about 84% and mine is about 91%. We're both pretty good at our stuff and fairly likely to succeed. But let's say the task is difficult and has a -4 penalty. Now you're down to 37% and I'm at 62%. I'm still not certain to succeed, but my higher skill helps me absorb more of the increased difficulty. Now, I'm not saying GURPS has the perfect skill system – far from it, the skills are too narrow, the costs are too high, and it's far too generous with penalties for everything. But that particular bit is pretty nice in reflecting how high skill has diminishing returns on normal tasks but is very helpful when things get difficult.

I think I've mentioned it before but I'd have loved to see a version of Pathfinder 2 where proficiency level (trained, expert, master, legendary) gates automatic success rather than allowing the attempt in the first place. They do have the Assurance skill feat you can take, but since that only counts proficiency bonus and not stats, items, and other buffs it's about equal to guaranteeing rolling a 5 or so.

 

[500 Toads]

Skill thresholds for ordinary (sometimes for unusual) tasks aren't that uncommon in BRP-based systems.

In Call of Cthulhu, for instance, it's assumed that pretty much any level of Drive Auto lets you handle normal driving (including normal vehicle mishaps) reliably; it's only meant to be tested at all for unusual circumstances, such as during vehicular chases, driving at unwise speeds with minimal visibility due to terrible weather, and so forth.

Reading through scenarios for its relative Delta Green will turn up such things as stuff that a character will be aware or be able to reliably do of if he has a relevant skill at a certain threshold (i.e. no roll), sometimes with pretty low thresholds (e.g. 10% in Art (Fashion) or 30% in History to recognize at a glance the time period from which somebody's suit comes from, with an alternative of an INT x 5 roll for those that don't qualify for an automatic success. There's cases where a Search of 30% would grant automatic success, while a Search roll at +20% gives others a chance; but passing oneself off as a native of a region might be hard-gated behind having a relevant specific language proficiency above 40% or so. Something requiring a great deal of scientific expertise in a particular field might be even strictly gated behind a 70% threshold.

 

[dbm]

Skill thresholds for ordinary (sometimes for unusual) tasks aren't that uncommon in BRP-based systems.

I would say that is a very common rule in general, now. Even GURPS says not to roll Driving skill for a trip to the shops, and with the now-common design concept of (generalising) “don’t roll a skill unless there is an interesting outcome for both results“ it seems to be becoming a default in GM advice (and good advice to be sure).