Post/Author/DateTime	Post
Romanus_Mortus 02-17-06, 05:06 AM	Here's something that I am sure most anybody who has played with the crunchy bits of D&D has surely noticed, but it confuses the heck out of me, so maybe someone can rationalize it for me. Why is a baseline, level zero human, with 10s in every ability, 55% likely to succeed at something of "average" difficulty? :confused: :confused: :confused: Trying to hit ac 10? well, if you roll a 10, you succeed Trying a task of average difficulty (DC 10)? well, if you roll a 10 you succeed. Mind you, I am not taking issue with the realism of this mechanic. I am taking issue with what looks to me to be a mathematical failure of logic. By making the rule "equal or greater than target number", and then making AC begin at 10, and DCs usually built on multiples of 5, you seem to be saying that 'average' does not mean as likely to fail as to succeed. But rather that you have a 5% better than average chance to succeed. Now I realize on a d20, the mathematical average of your rolls will be 10.5. But I also realize that if 10 is success, then you have 11 possible successes out of 20 possible outcomes... As I figure it, maybe they did that because "10" is a prettier looking number than "11", humans tend to prefer dealing with easily divisible numbers, even when division will never come into play - go figure. But from a strictly mathematical point of view, and in terms of making it easier to work out the likelihood of success and failure on a roll of 1d20, why did they skew things 5% in favor of success... I admit, this only bothers me because I am a bit neurotic about this sort of thing, and it has never really hampered gameplay (though it does make balancing things I design myself momentarily more difficult, as I have to keep in mind that numbers in D&D are all skewed by one in favor of success)... Anyway, just wondering if anyone on these boards could lend some insight into the logic behind the "equal or greater" convention, because it seems strange to me. And for the record, I've been playing D&D for over a decade and love it, but this has nagged at me since I started playing.
Fredrik Svanberg 02-17-06, 05:54 AM	If it bothers you that much, just change it so that you must roll better than the DC to succeed.
Romanus_Mortus 02-17-06, 05:56 AM	1) it doesn't bother me enough to change such a fundamental mechanic 2) that would nudge the balance on AC out of whack I am just asking if anyone has any thoughts as to why they did it the way they did, since it doesn't seem totally rational to me?
The White Sorcerer 02-17-06, 06:50 AM	Why is a baseline, level zero human, with 10s in every ability, 55% likely to succeed at something of "average" difficulty? Why not?
Romanus_Mortus 02-17-06, 06:59 AM	Why not? Because, mathematically, it makes alot more sense for you to have a 50% shot at succeeding to be average, not 55%... If you're not worried about the baseline statistical chance of failure, then it's not a problem. But from a development standpoint, it seems curious. Keep in mind that the implication also is that an AC of 1 guarantees a hit for anyone (unless you roll a 1). This *may* be the reason for AC using the equal or greater rule - because there is an implied chance of failure if you roll a 1 (though this seems a bit shaky to me even still). It also doesn't do much to explain how you can never fail a DC of 1. Like I said, it's not a huge issue, but it's curious to me that the developers would go with a mathematically skewed convention.
Feor 02-17-06, 07:30 AM	Consider this: if you're not trained in combat, and you're in a fight, what's easier to do: hit the other guy or not get hit yourself? From my experiance people such people are alot more likely to at least make contact in a fight than to avoid their opponent's blows. Also, most people can do tasks of average difficulty averagely. If someone asked you to make then a vase out of clay. You could do it. You wouldn't be able to make it a piece of art, and you'd probably be lucky if it wasn't lopsided, but you could do it. If someone handed you step-by-step instructions on how to forge a sword, and all the tools you'd need, you cold probably forge a sub-par sword. Average doesn't neccissarily mean as much chance of success as failure, it just means that that's what the normal example of that race is capable of. An average Elf is less likely to get hit in a fight than your average human but won't be able to take as many hits, since an elf with all 10s actually has 12 dexterity and 8 constitution. An average Half-Orc only has 8 intelligence, so he's less likely than your average human to be able to follow those instructions and forge that sword passably. The fact that the human "average" is above a strict 50% success chance isn't a broken mechanic. It represents our versatility and adaptability when doing things we aren't specifically trained to do.
celtredleg 02-17-06, 07:52 AM	I would argue that most people are a bit better than 50% rate, maybe as high as 60-65%. Else you would not have a functioning world. But if you start that high, then the players have less room to grow. The thing to remember, is that DnD is not about makeing sense for commoners, its about haveing fun as heros. I doubt the designers gave much thought to what commoners did, and dont care all that much even now. I dont especialy either, unless some day I play one.
Seeker95 02-17-06, 08:26 AM	ad hoc explanation to follow. You're omitting the aspect of "attempt" that the % compensates for. Most people don't try to do things they don't think they can do. That extra 5% builds in the greater than 50-50 chance of success reflected in our capacity for only trying those things at which we feel we are likely to succeed. (Some would say it is because we must be closely related to the Gallus domesticus. How is this possible when most people are known to be Ovis aries?)
Tyler Do'Urden 02-17-06, 08:42 AM	If that miniscule five percent of the possible outcomes really bothers you that much, just change the rule so that you have to exceed (rather than equal or exceed) the target number. Done. Simple. Seriously, this is D&D. If you don't like something, change it.
The White Sorcerer 02-17-06, 08:53 AM	Because, mathematically, it makes alot more sense for you to have a 50% shot at succeeding to be average, not 55%... Mathematics, schmatematics. Why must things make sense mathematically?
The Hive Custodian 02-17-06, 10:50 AM	I would recommend against changing the rules to force characters to have to beat the target number rather than meet it. The reason: All fighter-types would then essentially get -1 to attack rolls. All caster-types would then essentially get +1 to spell DCs.
babysamurai 02-17-06, 11:08 AM	All fighter-types would then essentially get -1 to attack rolls. All caster-types would then essentially get +1 to spell DCs. Good point. As if casters need to be more powerful, and Fighters...well, y'know.
Bruunwald 02-17-06, 12:18 PM	Mind you, I am not taking issue with the realism of this mechanic. I am taking issue with what looks to me to be a mathematical failure of logic. By making the rule "equal or greater than target number", and then making AC begin at 10, and DCs usually built on multiples of 5, you seem to be saying that 'average' does not mean as likely to fail as to succeed. But rather that you have a 5% better than average chance to succeed. "Average" has more than one meaning. I think in this case, it does not specifically imply equilibrium, but more a common result among many actions, and moreover, the common level of ability among many actors. In any case, it seems like you do harbor some iffy-ness over the realism of the mechanic, else why the strict interpretation? Personally, I believe that people do get more tasks right than wrong during a day. Look around you. If we didn't, your computer would always fry, your car would constantly break down, you would constantly be in danger from flying dishes, clumsy mailmen, stray bullets, airplanes crashing down in your front yard. I would say, if the mechanic is off or broken, it's that success isn't guaranteed enough. This will likely be an unpopular opinion, but I think human beings are largely well made, competent and clever creatures. We're smart. We make things. We learn. We improve. Push us and we get stronger and more competent, more skilled. Sure, we tend to think the guy in the car next to us is an idiot. But odds are he's going to make it home for the umpteenth time, unscathed, as are we.
DragonDeadite 02-17-06, 12:45 PM	For the same reason everything's on a scale of 1 to 10... because "Eleven" is too many syllables and people get their tongues twisted when saying it.... or maybe just because it's easier to think in terms of ten than terms of eleven. So sayeth the Dragon! :dragon:
Bruunwald 02-17-06, 12:50 PM	Because, mathematically, it makes alot more sense for you to have a 50% shot at succeeding to be average, not 55%... I just want to be clear on something here. You're saying, then, that 50% of the students in your high school got only 50% correct on their tests, 100% of the time, right? So half of your class flunked out and did not graduate? Correct? Because, as far as I know, over 60% competency has been the acceptable "average" for the past forty years or so. In some places, I think it's 68%. So by your logic, half of the people you knew in school must have flunked. The point I'm getting at is that an "average" is a measure of result across a segment, and not a guaranteed 50/50. Especially as applies to people. Your idea would work if people were machines or simply numbers. They're not. They're people. And when you measure people's performance against a strict scale based on results, you usually find that they get about 60% to 75% positive result versus a possible 50% positive result, in any given, uncomplicated task, on the average. Which means that for human beings, odds are not 50/50. They're skewed because we think. You have to juxtapose a strict 50/50 chance with average human competency to get a good game mechanic. Pure chance gives you a 50/50 result. But the simple intervention of a human being increases the chances of success, even if he's a total buffoon. I am willing to accept the minor bonus the game gives you in this regard. Because I believe that the intervention of a sentient being inevitably alters the odds from 50/50. Let me illustrate: If a human being flips a coin, the result is out of his hands. It's pure chance: 50/50. If a human being places a coin down, he guarantees that he can predict the outcome. Making it a task immediately changes the odds, even if the guy is a klutz. It removes chance.
Raven Dark 02-17-06, 01:22 PM	By taking 10, average people can accompish average tasks 100% of the time. It only becomes difficult when they are below average (such as an 8 strength person trying to climb a tree--taking 10 just doesn't cut it if the DC is 10). However, it works wonders for your average Joe.
DanjaNinja 02-17-06, 01:44 PM	Mathematics, schmatematics. Why must things make sense mathematically? So my degree doesn't go to waste?
igronimus 02-17-06, 02:48 PM	SOLUTION: Scratch the 2 off all the 20's on your D20. Replace any rule that says natural "1" with "0" and natural "20" with "19". An average guy (10 stat) attempting an average task (DC 10) will now succeed at an average rate (50% of the time). Voila! :cheer:
narukagami 02-17-06, 03:05 PM	Its been my personal experiance more than once that math and real life results don't always go hand in hand, especially statistics, no, specificly statistics. Except bell curves, because they actually take into consideration wild variants. I garentee that if you totalled together all the actual sucesses/failures that occure when you roll while playing dnd (as in actually count the rolls, don't bother with averages), the actual percents will be nowhere near 50% or what-have-you. Record them over a year and the numbers will vary wildly, it may very well get close to the statistics, but if I did it too, our results will probably totally clash, add in another person and the numbers will get even wilder. Never consider the numbers "hard" numbers, always think of them as 'general estimates'.
DanjaNinja 02-17-06, 03:15 PM	Its been my personal experiance more than once that math and real life results don't always go hand in hand, especially statistics, no, specificly statistics. Really? I've had quite the opposite experience. Maybe you're just not applying your math correctly. Funny story: I've got terrible "luck". Whenever there's a roll critical to the game, I fail it. I've rolled ones so consistently that my DM was convinced I was cheating. So I decided to take a sample of my rolls; not just any roll, but rather only rolls "critical" to the game. I stopped at about 4,000 rolls, and, without going into the details, all the statistics were basically what you would expect. Completely random. The point is, anecdotal experience is often very skewed.
Nom 02-17-06, 07:40 PM	For the most part, the exact mid-point of the mechanics doesn't matter. Whether we both hit 11/20 or 10/20 doesn't fundamentally alter anything. However, there is one place where it matters: caster level checks. These are supposed to be "equal chances" for both sides, which is why the "attacking" spell has a target number of 11 + CL rather than 10 + CL. For the rest of it, 10 is a convenient number, and it's more intuitive to say "must roll this much or higher" than "higher than this much".
residieu 02-17-06, 11:36 PM	Like I said, it's not a huge issue, but it's curious to me that the developers would go with a mathematically skewed convention. Because it makes the rules easier to explain. Things wouldn't look as nice if your base AC was 11.
PurdueDave 02-18-06, 12:55 AM	This makes no sense. There is no mathematical reason that people should succeed half of the time...even on average. Good professional baseball players succeed at the plate maybe 30% of the time (or 40% or so, depending on how you figure.) A good pool player can pocket shots at over 80%, no problem. Average people succed at routine tasks daily with nearly 100% success. No big deal. It depends on the skill and the difficulty of the task, just like the RAW.
Yak of Darkness 02-18-06, 05:42 AM	By taking 10, average people can accompish average tasks 100% of the time. It only becomes difficult when they are below average (such as an 8 strength person trying to climb a tree--taking 10 just doesn't cut it if the DC is 10). However, it works wonders for your average Joe.Ding, ding, ding! We have a winner! :cheer: DC 10 is used for "average" activities, not because a normal person has an exactly 50% chance to perform the task successfully, but because those kinds of tasks are the kind that an average human person (no ability mods, no skill ranks) in an average situation (no distractions, no circumstance modifiers) can perform by attempting to do an adequate job (taking 10). The only percentage that enters into it is the 100% chance your average joe gets, when nothing's working against him.
Seeker95 02-18-06, 08:27 AM	This makes no sense. There is no mathematical reason that people should succeed half of the time...even on average. Good professional baseball players succeed at the plate maybe 30% of the time (or 40% or so, depending on how you figure.) A good pool player can pocket shots at over 80%, no problem. Average people succed at routine tasks daily with nearly 100% success. No big deal. It depends on the skill and the difficulty of the task, just like the RAW.What you just described is exactly in keeping with the rules. A "good" baseball player has skill ranks. A "good" pool player has skill ranks. Hitting a baseball? Probably a DC of around 20. Maybe even 25. 30 in the pros. 35 with an all-star pitcher. Sinking a pool shot? Probably a minimum DC of 15. It climbs from there. Average tasks each day? DC 10. Take 10. 100% success.
Raven Dark 02-18-06, 12:06 PM	I was wondering how many posts it would take before someone would stop arguing about statistics and take notice of what I had to say. There are lies... Then there are DAMNED lies... Then there are statistics. - Mark Twain
Seeker95 02-18-06, 02:26 PM	RD, I'm sorry... did you say something? :P
Raven Dark 02-18-06, 04:44 PM	RD, I'm sorry... did you say something? :P Too cruel, dude. :heehee
Viper3220 02-19-06, 01:28 AM	Consider this: if you're not trained in combat, and you're in a fight, what's easier to do: hit the other guy or not get hit yourself? From my experiance people such people are alot more likely to at least make contact in a fight than to avoid their opponent's blows. <snip> Actually when someone teaches you how to block and you have the mentality to stay away from your opponent and not throw MULTIPLE attacks (flurry/go toe to toe) (because in real life attacking leaves you very vulnerable, that's why stunning the other person is a big part of defense, if you have that whole "good offense is defense" fighting style. Now I took a couple lessons in Martial arts, am overweight and not THAT coordinated and I can still not be hit by someone if I like to... Unless they get me somewhere where I can't move away like into a corner etc.... (this is excluding people who charge you and tackle you and try to just hammer your face in, in which then the time comes for you to pull out your knowledge of Jujitsu ;) ) anyway I disagree with this, if you're smart and you look for the guy you're facing to make a mistake and counter, it's SOOOO easy to avoid blows and hit back then you think (ASSUMING that you are both equally fast/strong also if one of you doesn't tire out first)
Romanus_Mortus 02-19-06, 01:50 AM	By taking 10, average people can accompish average tasks 100% of the time. It only becomes difficult when they are below average (such as an 8 strength person trying to climb a tree--taking 10 just doesn't cut it if the DC is 10). However, it works wonders for your average Joe. I think Raven Dark gets the cookie. This is the most reasonable answer. Though I could argue that the "automatic success" defaults should be "taking 11" and "taking 21" :P I also love how I explicitly stated that i was not interested in the realism portrayed by the number, but rather why the developers chose one abstraction over another. The thread, of course, was immediately innundated with references to athletics and protestations about whether 50% of my classmates failed tests in school (and in a proper educational system they would, btw). Thank you, RD, and the few others of you who offered purely constructionalist views on the matter. To those of you who care whether Babe Ruth had ranks in Profession: Baseballer - carry on, I'm not listening anyway :D
Phaseroth 02-19-06, 06:57 PM	What you just described is exactly in keeping with the rules. A "good" baseball player has skill ranks. A "good" pool player has skill ranks. Hitting a baseball? Probably a DC of around 20. Maybe even 25. 30 in the pros. 35 with an all-star pitcher. Actually, I think hitting a baseball would require the batter making an attack roll against the baseball's AC. The ball's AC, though, would be modified by the pitcher's Craft (fastball) modifier (I chose Craft, since a pitcher is often said to "make" the pitch. Weak, I know!). Or rather than giving the ball an AC, the hitter and batter would make opposed attack rolls. Dang, we could devote a whole thread to converting baseball to the d20 System! We'd have to start with the duration of a round, though ...
Seeker95 02-19-06, 07:59 PM	Actually, I think hitting a baseball would require the batter making an attack roll against the baseball's AC.Nope. Just an opposed Hitter skill made against the Pitch skill. :D