Objective vs. Subjective Difficulty

[Bill O'Dea]

Hi all,

First, very nice site. I've been lurking about for weeks, reading the articles and these forums, and I've been really enjoying myself. Thank you to everyone who wrote here, and I hope I can contribute.

Now for my first try at that. Please excuse me if I use a term incorrectly, as I'm still digesting those articles. Also, I've been away from RPGs for years and am just getting back into things.

I've been mulling over the traditional mechanic of 'Attribute+skill+difficulty+die vs. TN' and I got stuck on the 'difficulty' part. I can't remember if games I played in the past said the difficulty is objective or subjective, and I'm not sure which works in a Simulationist perspective. Using the example of two PCs shooting at a moving target in a system that adds mods based on difficulty of the task in question ....

Objective: This is a difficult task, so apply the Difficult mod to each PC.
Subjective: The first PC never shot a gun in his life, so apply the Difficult mod. The second PC is a Navy SEAL, so apply the Easy mod.

Subjective seems more realistic (what's easy for you might be very hard for me), but isn't that handled in part by better attributes or skills? I'm also concerned about what this brings to the GM. Subjective difficulty is likely decided by the GM, giving him a lot of control over the resolution. So ... in your opinions, should a difficulty mod be subjective or objective?

Again, please excuse any terminology misuse or etiquette breaches. I'll learn soon enough, or so I hope.

[Bankuei]

Hi Biggles,

Welcome to the Forge!  We like to use real names here, so if Biggles is your name, or a similar real(-ish) name you'd like to be addressed by, feel free to let us know.  I'm Chris, by the way, and most of us at least give a real name to work with in our signatures.

As far as  your question, I think the key thing to focus on, is what are the end probabilities you're going to get?  If changing the difficulty (target number, number of successes, whatever) increases or decreases probability, that's one thing.  If changing the bonuses the players get (+/- to the roll, number of dice rolled, whatever) increases or decreases the probability- that serves the same function.  Depending on your system, and the goals of play, you would choose one or the other, but really get the same end result.

The only thing you DON'T want to do, is use both at the same time.  Now, mind that one could be a factor of player control, and another of GM control, but you don't want to use both for GM control of difficulty- because there's really no reason to.

And, though both of these types are equally useful, a more important question to ask- is what is the point of  your game?  You'll hear that a lot on these forums, because the answer to that question determines all the "hows" and "whys" of the mechanics questions.  For example, it's a perfectly legitimate reason to determine that bonuses and penalties are based on the number of dice you get to roll- just so that people get a tactile sensation based on how many dice are in their hands.  It's also legitimate to determine that you might want to increase the number of successes rather than take away dice if your game uses "exploding" dice mechanics... overall, all these things depend upon the specifics of your game and the goals you have.

Chris

[Bill Cook]

Biggles:

Where are you getting this formula from? Chris (Bankuei), I read, is assuming it's a game you're developing. Is that the case?

There's definitely some overlap in what you're describing. It sounds like your goals are some kind of metaphysical common sense for combat. And you say "realistic" to describe that. So consider: two characters shoot tin cans off a fence rail. Ed has been firing guns since he was nine years old. It's John's first time. Ed's experience should impact favorably. John's will not.

Now they're shooting at a squirrel in a tree. It's zipping around from one branch to the next, trying to avoid being shot. Experience impacts the same; but the overall difficulty is greater.

If the range of everything is 1 to 10, the numbers would look like this: Ed (Hand-Eye Co-ordination: 5, Shooting: 6); John (Hand-Eye Co-ordination: 5, Shooting: 1); Difficulty (tin can: 1, squirrel: 7); TN: 13. To me, the following formula makes more sense: Attribute + Skill + d10 vs. TN + Difficulty. So Ed needs 3+ for the tin can and 9+ for the squirrel; John needs 8+ for the tin can and cannot possibly hit the squirrel (except on a roll of 10, indicating a critical hit).

That's a blasé, generic way of approaching whatever realism means.

[Bill O'Dea]

Chris and Bill: Thank you for your replies.

I am working on a system and the thought of 'what's a difficult task' came up while I was thinking about it. I'll post more in the Indie Games forum when I have more to post.

Bill Cook's reply appears to use an objective difficulty rating: shooting a tin can is Difficulty 1 and shooting a moving squirrel is Difficulty 7. I'm not so concerned about where Difficulty comes into the equation (+ Difficulty on the TN side is the same as - Difficulty on the Attribute side) but in how to determine what Difficulty to apply.

To continue Bill's example, Ed has Shooting 6 and John has Shooting 1. Would shooting a tin can be Difficulty 1 for both? For Ed, shooting a tin can should be child's play and Difficulty 1 sounds appropriate. But if John has never shot a gun before, even shooting a tin can could be moderately difficult (adjusted by attributes like hand-eye coordination, but you get the idea). Should John get Difficulty 4 or something similar since the task is has higher difficulty for him?

PS: Chris, thanks for the heads-up on name usage here. I've changed things to reflect my real name. Nothing to hide, I swear!

[Bill Cook]

It's like Chris was saying: just don't reflect the same thing twice. For this example, everything's fixed. It might not be intuitive that Difficulty is constant among characters of differing skill. But since skill is referenced, the formula provides the kind of probabilities you'd expect.

I think you're conflating Difficulty with the formula result. If you label it as Target Number (TN) and re-orient, it'd look like this:

TN = 13  + Difficulty - Attribute - Skill

.. where TN is the number (or higher) needed on a d10 to succeed. It's all the same stuff; just a different way of naming and arranging things.

[Justin Marx]

Bill C's point is straightfoward and pertinent - that Objective Difficulty equates to the TN, and that Subjective equates to the Skill/Attribute level. You can dance around and make these inversed if you like (which I am doing) which may make calculation simpler, but the mechanic is the same.

However, I see the term 'Subjective' difficulty as something apart from skill level. Impairment from wounds, lack of courage, sweat in the eyes, etc. In simple TN mechanics, these act as penalties to the outcome. Or they can be percieved as penalties to the skill itself. (Of course not only penalties - Dutch courage, magic potions, buffs of all kinds etc can work as bonuses).

This may seem like a redundant question - but which of those two options seems simpler if we are working with straightforward TN mechanics? Is it easier for people to read:

1) TN = (13 - Skill +/- Subjective mods), now roll over it or
2) TN = 13, roll + Skill + Subjective mods.

May seem a little stupid, but which do people find more intuitive? I am canvassing for opinions, but educated ones I hope, which is why I am broaching it here.

Bill O, I hope I am not derailing your thread too much here. I am working with similar TN mechanics myself.

[simon_hibbs]

Objective: This is a difficult task, so apply the Difficult mod to each PC.
Subjective: The first PC never shot a gun in his life, so apply the Difficult mod. The second PC is a Navy SEAL, so apply the Easy mod.

I realy don't see the problem here. If the game includes a skill modifier, and SEALs have high firearms skills, then why would you want to apply a different difficulty modifier? If the game actualy required this, I'd say it's broken because the last thing I as a GM wqant to have to do is apply extra ad-hoc modifiers to make sure that characters who should succeed ast certain tasks anyway actualy do so.

Note that I have actualy played games like this - where the players were supposed to be the best of the best, but the actual game system made sure they failed at stuff all the time. It's a real pain in the arse.

The interesting debate, and it's been rehashed here many times, is between action resolution and conflict resolution. This is simple action resolution though, which is as old as RPGs.

Another factor is "Story Modifiers", I'm sure there's a better term but basicaly the question is "Is this conflict important to the story/players/characters/plot development?" If not make it easier than normal, or just don't roll and have the players succeed automaticaly. Important conflicts should use the full normal difficulty because that's where you want the tension and drama.


Simon Hibbs