An Argument for Ability Checks in OD&D...

[thegreyelf]

Transplanted from my blog:

I'll preface this by saying I'm a fan of ability checks. Always have been. I also understand and appreciate the ultra-light rules approach of OD&D. The more systems you bolt on, the more of a Pandora's Box you open up, risking making OD&D something it's not. Up till now most (okay, all) of the systems I've toyed with herein were modifications of existing systems (Chainmail for combat and Saving Throws, for example) rather than the addition of new ones.

However, I'm considering an Ability Check system.

"Why?" cry the traditionalists. "Why would you do something so...new school with OD&D!?"

A very valid question. And the simple answer is, because it works and doesn't hurt the game. It allows me to adjudicate pretty much any situation without resorting to judgment calls and DM fiat with which my players may vehemently disagree. So long as a system doesn't hurt or slow down the play, I'd argue, it's not necessarily bad to have a neutral way to accomplish these things.

This being said, it's also important to note that an Ability Check system should be used sparingly. If a human Fighting Man with Str 18/00 tries to hold a door shut against a couple Hobbits with strength 10 and 11, be serious: no roll is necessary. He can hold the door. But what if he's trying to hold the door against two other men with Strength 16 and 17, respectively? That's a more difficult task indeed. You could simply rule based on the story that he does it. You could make the other two each roll an Open Doors check. There's lots of ways to do it. An Ability Check system simply puts it on even ground across the board.

There are two ways to handle this in OD&D. The most basic is roll 3d6 and attempt to get under (not equal to or under) your Ability. Thus, if you have Str 17, you need to roll 16 or lower to succeed. Resisted checks are adjudicated based on whoever succeeds by a higher margin.

Another way is a "roll over" system with a target number. Since I've been using 2d6 for a lot of things, that seems a good option. The first step would be to grant Ability bonuses. The easiest way there is to import (and expand for % strength) those from the Moldvay Basic D&D books:

3: -3
4-5: -2
6-8: -1
9-12: 0
13-15: +1
16-17: +2
18 (18/01-50): +3
18/51-00: +4

The average roll on 2d6 is 7. Therefore, the basic target number for a task of average difficulty would be 7. Bonuses and penalties for tasks of greater or lesser difficulty can be granted on the same scale as the table: difficult tasks are -1, very difficult -2, and extremely difficult -3, whereas easier tasks are at +1, simple tasks at +2, and basic tasks at +3, though basic tasks should rarely be rolled for unless there is some serious consequence for failure and the character is performing under duress.

Resisted tests between two people, naturally, function based on the higher roll winning.

Just some idle ponderings. At very least it functions as a fallback for situations where the DM isn't quite sure how to adjudicate.

[coffee]

I don't think ability checks are so "new school" as all that. There were many different systems back in the early days for determining how likely things were to occur. Ability checks are one of the more fair ways, and I've seen a few different schemes for using them.

But this bit here:

Jul 22, 2009 9:16:26 GMT -6 thegreyelf said:

You could simply rule based on the story that he does it.

is much more "new school" than ability checks will ever be (in my opinion).

"Story as a driving force" was totally alien to how we played even when I started, in the early 80s. Story was simply what happened once we were playing -- you could only see it in retrospect. DMs may have planned what they wanted to happen, but it didn't take too many times of being totally surprised by what the players did to disabuse them of that idea.

"Let the dice fall where they may!" is the rallying cry of the old school movement (as far as I'm concerned), and ability checks fit right into that.

(It does, however, open the door to stat inflation and variant methods of character creation. But so do many other things.)

In short, if it works for you -- use it! But come back and let us know what happened either way. We're always curious.

[Finarvyn]

Jul 22, 2009 10:08:00 GMT -6 coffee said:

I don't think ability checks are so "new school" as all that. There were many different systems back in the early days for determining how likely things were to occur.

Yeah, we did stuff like this in the '70's. The Abillity Check meant that we didn't have to bother with a skill system.

One of my early thief characters was named Dex Check. ;D

[aldarron]

Its my understanding from the comments of Arneson, Svenson and others that the reason Arneson invented ability scores in the first place was for use as a 2d6 roll under checking system. The idea that other bonuses and penalties, and side effects should result from ability scores seems to have come later.

[chronoplasm]

You might consider allowing a 'Take 10' rule.
That is, perhaps players may be given the option, in certain circumstances, to forgo actually rolling dice and instead assume the dice land on average.
Just a thought.

[thegreyelf]

Chronoplasm, I don't think a take 10 rule is necessary because if you are gaming in the old school mentality, ability checks will be used very sparingly, and only when a hard adjudication is really needed. On average situations where there is little pressure, characters will just succeed. Presumably these average situations can be scaled by the DM for those with higher or lower Abilities.

[chgowiz]

I tend to use ability checks when the outcome isn't certain (random possibilities/factors) or the difficulty of doing something is "Very Hard" to "Impossible". I have been doing the d20 route - applying penalties where I see fit.

Why no bonuses? Simple, if someone has a situation where I have to do an ability check and a bonus would apply, I'm more likely to just say "yes." It's the chance of failure that the ability check is "saving against".

[apeloverage]

When I played Basic D&D we always used ability checks (roll equal to or under your ability on a d20 to succeed). I was surprised to learn that this wasn't an official rule.

My problem with it is that it can make DEX overly powerful.

[jcstephens]

OK, what are we trying to accomplish here? Combat needs a random element, because randomness adds uncertainty and tension to combat. Victory should never be inevitable, in order to give an incentive to avoid combat if possible. The same applies to traps and other deliberately placed lethal obstacles. I prefer players to think their way around a problem, and any reasonable plan will automatically succeed, but if they want to stake their character's lives on a roll of the dice, I'll allow it.

[coffee]

Some people love to roll dice.

Some of us like to, but prefer to have a more direct control over whether our character lives or dies.

And some people would just as soon not roll dice at all.

The great thing about D&D is that it's big enough to accommodate all of these styles of play.

[thegreyelf]

Indeed. And sometimes a DM just isn't sure what call to make in a given situation. Every DM has been there and anyone who says he or she hasn't is lying. Personally, I dig having something quick, easy, and standard in place for those rare occasions. Doesn't mean every time you want to walk across a room you have to make a Dex check. But why do we have Open Doors or Listen rolls, if combat and traps are the only situations where a random element is needed?

[jcstephens]

Coffee's point about different styles is well taken. I'm prejudiced against skill and ability checks, because I believe they lead to bad habits. I encourage my players to fear the dice, and to reach for them only as a last resort, as my way of keeping the game about roleplaying.

But that's just my opinion.

[machfront]

Jul 23, 2009 10:15:19 GMT -6 apeloverage said:

When I played Basic D&D we always used ability checks (roll equal to or under your ability on a d20 to succeed). I was surprised to learn that this wasn't an official rule.

In a way, it was. Since you mention Basic. Check Moldvay Basic, page 60 under "There's always a chance."

[coffee]

Jul 23, 2009 22:30:00 GMT -6 jcstephens said:

Coffee's point about different styles is well taken. I'm prejudiced against skill and ability checks, because I believe they lead to bad habits. I encourage my players to fear the dice, and to reach for them only as a last resort, as my way of keeping the game about roleplaying.

But that's just my opinion.

And I'll bet your players are all the cagier for it. I envy them. I used to have a good, tough DM back in the day, and I miss his world. He was downright Gygaxian.

But Kesher's doing a pretty good job, these days. I'm having a good time in his game. I even got to do some mapping last weekend -- there are some skills that have rusted over the years!

It occurs to me that the last time I ran OD&D I went ahead and used ability checks. For those of you who think it's too easy (or it makes DEX too powerful), go ahead and have them roll under HALF their DEX.

Or make it a Percent roll. Remember, as the referee, you can structure the odds any way you like to accurately reflect the chance you see as the most likely. The players don't have to like it. Come to that, they don't even have to survive it.

But if they keep coming back, you know you're doing it right.

[irdaranger]

Jul 23, 2009 22:30:00 GMT -6 jcstephens said:

Coffee's point about different styles is well taken. I'm prejudiced against skill and ability checks, because I believe they lead to bad habits. I encourage my players to fear the dice, and to reach for them only as a last resort, as my way of keeping the game about roleplaying.

I LIKE this. Exalt!

This somehow, in one sentence, encapsulates exactly the type of environment I want to encourage among my players - a feeling that the dice are risk embodied; the risk of death.

Maybe I should make a banner to clip to the outside of my DM's screen - "The Dice are Tools of last Resort; for They contain both Fortune and Doom."

Oh, as for the OP - the one problem I always had with stat checks like "roll under your stat on d20" is that they don't really help encapsulate how much of a better chance a 18 Str character has vs. a 15 Str character. I think when dealing with opposed Stat checks (like in your holding the door example) you ought to roll 3d6, and whomever rolls under their stat to a greater degree wins.

Play Example: A 18 Str Fighter ("Bob") is shoving a 15 Str Fighter ("Mike") and the DM demands opposed Str checks to resolve. Bob rolls a 13 and Mike rolls an 11, but since Bob's "under-roll" is 5 (18-13), that beats Mike's under-roll of 4 (15-11). Bob wins, even though he rolled higher.

[snorri]

In the 18 STR vs 15 str. style of situation, I use this method : the highest score roll firts 1d20 under his ability score. If the roll is under his score, he win. After all, he's the best. If he fail (by rolling over), the lowest score guy rolls. He the roll is under his score, he win. If he fails, the higheest score win.

This method is quick and easy, and makes sur the best score win most of the time....

[aldarron]

The way I handle opposed ability checks is to make the difference a positive modifyier to the one who has the adavantage. Str 18 working against strength 15 - the strenght 18 character has the advantage by +3 so its 18 + 3 = 21 and thats automatic. If it were a strength 12 and a strength 13, the strength 13 player would have a one point advantage and so would have to make a roll under 14 to win. If he fails, he loses.

[billhooks]

I came up with an angle where I compare ability scores and if it's a tie both sides have a 50% chance to win, otherwise the high score has a 75% chance. The idea is that even a 3 isn't so crappy that you never have more than an outside chance, and even an 18 isn't so great that you can be arrogant about your chances. As DM I can roll ability scores spontaneously for monsters, NPCs or abstract "adversity". I haven't actually tried it yet though.

[Mordorandor]

For those who use ability score checks (I don't, btw), I'm curious to know things like,

(a) how often do you call for them?
(b) what do those situations entail or look like?
(c) do you set a minimum score (a floor, if you will) for any task before a skill check is made? (say, to lift a boulder: you need an 18 min to even get a chance to roll?)

... etc.

I generally consider the ability score, attempt to relate that to the situation, factoring different tier type feats into normal, Hero, or Super Hero categories. Then just make a declaration.