[D&D] Actions the Rules Don't Cover

[Matthew]

To prevent further derailment of Marshall's My Experiences with 4e thread, I thought I would start a new one. Basically, we're talking about how each edition handles actions not covered by the rules.

4e DMG, p. 42.

Actions the Rules Don't Cover

Example: Shiera the 8th-level rogue wants to try the classic swashbuckling move of swinging on a chandelier and kicking an ogre in the chest on her way down to the ground, hoping to push the ogre into the brazier of burning coals behind it. An Acrobatics check seems reasonable.

This sort of action is exactly the kind of thinking you want to encourage, so you pick an easy DC: The table says DC 15, but it’s a skill check, so make it DC 20. If she makes that check, she gets a hold on the chandelier and swings to the ogre.

Then comes the kicking. She’s more interested in the push than in dealing any damage with the kick itself, so have her make a Strength attack against the ogre’s Fortitude. If she pulls it off, let her push the ogre 1 square and into the brazier, and find an appropriate damage number.

Use a normal damage expression from the table, because once the characters see this trick work they’ll try anything they can to keep pushing the ogres into the brazier. You can safely use the high value, though— 2d8 + 5 fire damage. If Shiera had used a 7th-level encounter power and Sneak Attack, she might have dealt 4d6 (plus her Dexterity modifier), so you’re not giving away too much with this damage.

3e DMG, p. 25.

Adjudicating Actions Not Covered

While the combat actions defined in the Player ’s Handbook are numerous and fairly comprehensive, they cannot begin to cover every possible action that a character might want to take. Your job is to make up rules on the spot to handle such things. In general, use the rules for combat actions as guidelines, and apply ability checks, skill checks, and (rarely) saving throws when they are appropriate.

Example: A monk wants to jump up, grab a chandelier, and swing on it into an enemy. You rule that a DC 13 Dexterity check allows the monk to grab the chandelier and swing. The player asks if the monk can use his Tumble skill, and you let him. Ruling that the swing is somewhat like a charge, you give the monk a +2 bonus on the roll to see if his dramatic swinging attack succeeds.

2e First Quest, p. 10.

Dungeon Master Rules

• DMs decide what happens. If necessary they just make it up.
• DMs decide what percent chance an action not covered in the rules has of working. If a Dungeon Master's d100 roll is less than or equal to that number, the action worked.
• DMs are always allowed to decide that a character's action automatically does or does not work. DMs are always allowed to change a die roll if they think there is a good reason.
• Dungeon Masters should always be fair.

Example One: There are no rules for climbing out of windows. However, this is such a simple action the DM might decide it works automatically.

1e DMG, p. 110.

Rolling the Dice and Control of the Game

There will be times in which the rules do not cover a specific action that a player will attempt. In such situations, instead of being forced to make a decision, take the option to allow the dice to control the situation. This can be done by assigning reasonable probability to an event and then letting the player dice to see if he or she can make that percentage. You can weigh the dice in any way so as to give the advantage to either the player or the non-player character, whichever seems more correct and logical to you while being fair to both sides.

[AKA_Bait]

Things did seem to get more complicated as each edition rolled by didn't they?

[Matthew]

No doubt.

[Tormsskull]

You can weigh the dice in any way so as to give the advantage to either the player or the non-player character, whichever seems more correct and logical to you while being fair to both sides.

This makes the most sense to me, as it allows the DM to adapt to whatever playstyle the group wants. Want it to be a real gritty game where high-flying acrobatics are virtually nonexistant. No problem, make these (and related checks) very difficult.

Want a Crouching Tiger Hidden Dragon type game? No problem, let players describe that gravity-defying move they are pulling off and give them a good chance at success.

[kamikasei]

There just seems to be an increase in guidelines and examples provided, not really complexity.

1e: come up with a probability that makes sense and is reasonable.

3e: same, with some example numbers and a mention that you may wish to reuse rules for certain events to cover distinct but conceptually similar ones.

4e: same again, but stepping through the idea of calibrating the outcome of successes to what other abilities would let the player achieve at the same level.

[Adumbration]

There just seems to be an increase in guidelines and examples provided, not really complexity.

1e: come up with a probability that makes sense and is reasonable.

3e: same, with some example numbers and a mention that you may wish to reuse rules for certain events to cover distinct but conceptually similar ones.

4e: same again, but stepping through the idea of calibrating the outcome of successes to what other abilities would let the player achieve at the same level.

Except that in 4e you actually have to look it all up in tables, instead of making it up on the spot.

[Jayabalard]

There just seems to be an increase in guidelines and examples provided, not really complexity.

1e: come up with a probability that makes sense and is reasonable.

3e: same, with some example numbers and a mention that you may wish to reuse rules for certain events to cover distinct but conceptually similar ones.

4e: same again, but stepping through the idea of calibrating the outcome of successes to what other abilities would let the player achieve at the same level.

The language in the 1e block is much looser; it's describing an alternate way of handling it instead of just adjudicating it on the spot. The 3e and 4e text seem to saying "this is how you do it" in a much more concrete fashion. There's also a higher focus on consistency on 3e block and even more so in the 4e block.

[Oracle_Hunter]

Gosh, Matthew, you are a thread-spawning machine

Anyhow, I'll give my brief spiel on why 4e Actions The Rules Don't Cover (ATRDC) is superior:

Spoiler

Show

No matter what system you use, you're going to run into times when the players want to do something that seems reasonable but isn't explicitly detailed in the rules. Well, except for pure Narrative games and other Rules Light systems, but we're talking D&D here.

In all these situations, the players don't care what the rules say - they know what they're doing isn't in the rules - so these ATRDC approaches are only useful to the DM.

With that said, it is easier for a DM to keep actions in line with the rest of the game system if the ATRDC gives a simple, non-arbitrary framework for the DM to adjudicate.

In 1e, the ATRDC is at its most arbitrary; the DM picks a number out of the air and asks for the player to roll. Any differences in character skill will be weighed arbitrarily by the DM and used as a modifier. Whatever the DM chooses has no real relation to the other rules available in 1e (like THAC0 or Saving Throws) and, to hear Nagora say it, are often the better choice than actually playing the game as described in the book. This can, ultimately, raise the question of why you are playing a system where you just make everything up on your own - but more immediately, it can result in wildly out-of-balance effects. Once the party Thief discovers that carrying a bag of sand around to throw in people's eyes is always better than stabbing with a dagger because of a DM ruling, why would he ever use his dagger?

In 3e, the ATRDC tries to speak within the framework of the rules, using skill checks and such. However, it had no table of appropriate DCs, nor tables of appropriate damage, so we have the same problems we see in 1e: if the DM accidentally rules some maneuver to be far better/easier than actually using the 3e rules, then that's just what the PCs will use. The problem in 3e is not that bad if for no other reason than there is very little which is not covered by some aspect of the rules, somewhere (I guess throwing sand again).

In 4e, the ATRDC not only speaks within the framework of the rules, but it provides appropriate DCs and damage for every level, and it refers to them using natural language description like "easy" "medium" and "hard" and "low damage" "moderate damage" and "high damage." Thus, a quick reference to DMG 42 is enough to quickly resolve any improvised actions without the need for any ad hoc number generation.

Now, it should be noted that I do not think that ATRDCs should answer the questions for the DM without any DM input. Instead, I prefer for a rules system to provide the necessary system variables to help me translate my concepts of an action (swinging on a chandelier is "medium" difficulty, and a boot to the face can be "moderate damage"). I am not privy to all of the number crunching that goes into making a system, and I'd prefer not to pull such numbers out of thin air.

Summary
- An ATRDC should help the DM to convert player input into rules-sensible results. DMs are not privy to the numbers that go into making a game system, and they should not make up such significant numbers if they can avoid it.

- If a DM miscalculates the system numbers, he may produce a new action that invalidates the very purpose of the rules system you are using (e.g. if a Rogue is more effective using an ATRDC sand-throwing attack than using a dagger, why would he ever use the dagger?). If you are not using the rules included in the game, why are you playing that system at all?

[nagora]

The thing is that a lot of the time, the extra steps in 3e+ are strangely counter-productive. If a character wants to, say, run up a fallen roof beam and jump over the wall into the river, I may think to myself "oh, maybe 30% chance given the smoke, the burning oil on the beam and the fact that they have a Dex of 8". The player then rolls d% and we see what happens.

If I want to translate that into "official" 3e/4e speak, I have to try to work out what DC gives the desired chance for that character. What's the point of that extra calcuation? As the DM, if I have an idea of the difficulty I can go straight to the percentage; and if I don't then I can't pick a DC instead because I've not decided on the difficulty!

I've tinkered with many methods of standardising the difficulty of tasks in D&D and other games and it always runs into this problem that the process of judging the difficulty is enough for me to pick a percentage chance and forget any other "clever" or "eligant" transformations into penalties, bonuses, extra dice or whatever and just get on with playing the game.

This effect is compounded by the totally weird spacing of DCs which give people far too big a range between auto-fail and auto-succeed, which ultimately can be traced back to the original design of the skill system in 1e OA which used a d20 for no good reason. The original designer seems to have thought that using the same die for skills and combat was in some way intuative without considering the effects.

In combat, rolls are iterative and one lucky roll will probably be balanced (unless you use crappy critical rules) by a later poor roll. But skill rolls like the one's we're talking about are usually all-or-nothing and the effect of that big spread is to totally disrupt the players and DM's ideas about what is and isn't likely.

What would be intuative, would be for a character with, say 5 levels in acrobatics to have the same chance to outperform a character with 1 level in acrobatics as a 5th level fighter has of beating a 1st level fighter.

But here we start to see another design issue that 4e is going to have to face: skill challenges that use skills multiple times are more like combat and the luck does have a chance to even out. This means that level 5 is acrobatics may (I've not played it, but I'm basing this on my experience of d20) in fact not mean the same level of ability in different situations as others.

For example: a single roll of d20+5 has a 25% chance of rolling 20 or more. The chance of rolling 24 or more twice duing a skill challenge is only 6%, and three times is 1.5%. So, the same skill can go from "perfectly decent chance" to "you'd have to be desparate" depending on how the DM applies it. I think this could cause trouble if it wasn't for the fact that I think skill challenges will simply die away and become a forgotten experiment.

[Yakk]

The thing is that a lot of the time, the extra steps in 3e+ are strangely counter-productive. If a character wants to, say, run up a fallen roof beam and jump over the wall into the river, I may think to myself "oh, maybe 30% chance given the smoke, the burning oil on the beam and the fact that they have a Dex of 8". The player then rolls d% and we see what happens.

If I want to translate that into "official" 3e/4e speak, I have to try to work out what DC gives the desired chance for that character. What's the point of that extra calcuation? As the DM, if I have an idea of the difficulty I can go straight to the percentage; and if I don't then I can't pick a DC instead because I've not decided on the difficulty!

So, how about the character next to him, who is a bit clumsier? Or the character who is a lot clumsier? If they try the same thing, what is there chance?

Meanwhile, when you make that decision, are you deciding "the player's action should be discouraged" or "the player's action should be encouraged"? Are you aware at which point the action becomes "way better than anything else the player could do" or "that was a pure waste"?

Do you see any utility in, say, having a table what kind of results would often be "worth it", damage and success-chance wise?

When a player rolls a d20, does it matter much to you how large of a modifier they have on that d20, or rather "you rolled low, so that's a bad result -- you rolled high, a good result"?

What would be intuative, would be for a character with, say 5 levels in acrobatics to have the same chance to outperform a character with 1 level in acrobatics as a 5th level fighter has of beating a 1st level fighter.

But here we start to see another design issue that 4e is going to have to face: skill challenges that use skills multiple times are more like combat and the luck does have a chance to even out. This means that level 5 is acrobatics may (I've not played it, but I'm basing this on my experience of d20) in fact not mean the same level of ability in different situations as others.

For example: a single roll of d20+5 has a 25% chance of rolling 20 or more. The chance of rolling 24 or more twice duing a skill challenge is only 6%, and three times is 1.5%. So, the same skill can go from "perfectly decent chance" to "you'd have to be desparate" depending on how the DM applies it. I think this could cause trouble if it wasn't for the fact that I think skill challenges will simply die away and become a forgotten experiment.

You do know that skill challenges flatten the math?

Suppose you have a task you have an Y% chance at.

Now suppose you have to make K successes before K failures. What is your chance of success?

As the number K increases, the impact of each +5% chance away from 50% grows.

If you then add in non-game-ending negative consequences to failure, and you have just generated a system that is somewhat like combat -- each attack roll has a negative consequence on failure, but you do enough that in the end the dice rolls average out.

...

Remember, DMs are imperfect.

It is easy to fall into the trap of "roll a d20 -- oh, you rolled a 2, that's low, you screwed up", "but, my character is a grand-master acrobat trained from birth with a +20 to balance -- and bob over there is a clumsy barbarian with a -2 to balance. Why did he succeed on a 17?" style problems.

You can easily run into the "I run up the golem and stab it in the eye" -- DM says "ok, it makes an OA, you have a 1/5 chance of making it up the golem, and then you do normal damage."

Or the "I throw sand in it's eye", and "the enemy is blinded, and you can kill it in one blow!" problem.

In each, the DM made a mistake -- not taking character concept differences into account in the fiction (which is a huge advantage of using character-agnostic DCs for problems -- players who choose to make a character concept who is supposed to be a super-balancing fiend lose that input if the DM ignores that facet of the character), throwing so many checks and obstacles in the way of the action that the player was really better off being told "no, you really don't want to do that" (and a DM can do this accidentally, without even knowing they are doing it, if they aren't a mathematical savant), and finally producing a tactic that is so good that it breaks the game fiction and either having to make it not work that way anymore, or ... have cheese problems.

The table on page 42 gives you:
1> A set of character-agnostic DCs. This means that when a player makes a character that is good at something the game world fiction responds.

2> A set of mechanically-based results. This helps solve the "too good" and "too crappy" results of an action, both of which cause problems.

In short, it is a tool that helps you make decisions.

[MartinHarper]

nagora - the difficulty I have with that approach is that it requires me to know and remember that character X has a Dexterity of 8 and is wearing heavy armour and used to compete in the Steeplechase. Without that information, I find it easier to say "make an Acrobatics check, DC 15". This also means that when the next character tries the same stunt, who has a Dexterity of 16, is naked, and is scared of heights, I don't have to think of another arbitrary number - I can use the same arbitrary number I used last time.

Except that in 4e you actually have to look it all up in tables, instead of making it up on the spot.

I have yet to look at page 42 during play. My party are level 1, and it's easy to remember 5=Easy, 10=Medium, 15=Hard. For an action against a monster I use an appropriate defence: Fortitude, Reflex, or Will. Because my party aren't going to gain three levels in a single session, I can copy the damage expressions onto my DM crib sheet.

The 4e wording is the first to remind DMs that players doing crazy stuff is something to be encouraged, which I think is a welcome improvement.

[hamlet]

nagora - the difficulty I have with that approach is that it requires me to know and remember that character X has a Dexterity of 8 and is wearing heavy armour and used to compete in the Steeplechase. Without that information, I find it easier to say "make an Acrobatics check, DC 15". This also means that when the next character tries the same stunt, who has a Dexterity of 16, is naked, and is scared of heights, I don't have to think of another arbitrary number - I can use the same arbitrary number I used last time.



I have yet to look at page 42 during play. My party are level 1, and it's easy to remember 5=Easy, 10=Medium, 15=Hard. For an action against a monster I use an appropriate defence: Fortitude, Reflex, or Will. Because my party aren't going to gain three levels in a single session, I can copy the damage expressions onto my DM crib sheet..

Yeah, maybe, except that many of us old fogies solve this with a quick mechanic called "the ability check." Takes about 3 seconds, 6 if you want to apply modifiers.

Player1: I want to run up the burning beam and onto the second floor balcony to escape.
DM: Fine, roll a DEX check, call it -4 because of the smoke and burning oil on the beam.
Player1: *rolls d20* That's a 12, which at least 4 under my DEX. I made it!
DM: Cool. Now the Ghoul Lord on the 2nd floor can melee you.
Player1: Oh . . .
Player2: I want to do the same thing and try to help out my friend!
DM: Same check.
Player2: *rolls d20* Oh no, that's more than my DEX!
DM: *roll's dice* You fall off about halfway up the beam. You take 4 damage from smashing face first into the floor and are no on fire. You'll take damage from that as next round starts.
Player2: Ouch!
Player1: Oh my god stop eating my eyes! Oh no, it's going to kill me! Help me!
DM: Heh, anybody else want to give it a try?
Remaining Players: Nope, sorry dude, you're on your own. *PC's rush out front door and leave idiots to their fate*

[Oracle_Hunter]

Yeah, maybe, except that many of us old fogies solve this with a quick mechanic called "the ability check." Takes about 3 seconds, 6 if you want to apply modifiers.

The problem with the ability check is that it didn't scale with level. No matter how much time you spend running on narrow ledges or swinging on chandeliers, you have as good a chance of making the run at 1st level as you do at 20th. This might be OK for a Fighter, but for the Rogue who went from a 50% chance of climbing walls to a 99% chance of doing it in 20 levels, he's going to look pretty silly having never improved his balance.

Plus, opposed ability checks were always a huge problem. The famous Wizard-Fighter arm-wrestling challenge for one.

[Hal]

In a mostly related note, I try to mitigate this by anticipating player actions. That is, if I'm building a room with a chandelier, then I try to work out ahead of time what they need to do to climb onto the thing, or what the damage is if it's cut down and falls on someone.

This doesn't skip the problem of figuring out what those numbers should be. But it does at least bypass the "making up numbers on the spot" problem.

Obviously, not everything you could prepare comes up, and you can't always prepare for everything, but I think it's good practice to at least anticipate these things. If you're putting the PCs around a bonfire, you ought to be ready to say what happens when someone lands in it.

[hamlet]

The problem with the ability check is that it didn't scale with level. No matter how much time you spend running on narrow ledges or swinging on chandeliers, you have as good a chance of making the run at 1st level as you do at 20th. This might be OK for a Fighter, but for the Rogue who went from a 50% chance of climbing walls to a 99% chance of doing it in 20 levels, he's going to look pretty silly having never improved his balance.

Plus, opposed ability checks were always a huge problem. The famous Wizard-Fighter arm-wrestling challenge for one.

That's right, it doesn't automatically scale with level, and that's cause you don't suddenly become more dextrous because you gained a level.

Of course, if you felt like it, you could always adjust based on level and say, for instance, that a higher level person who's been doing this kind of stuff for a while gets a bonus to his roll equal to, say, the number of chest hairs he has, but I hardly see the neccessity. Your prowess in battle doesn't improve your balance while pulling stupid stunts.

Plus, ability checks have NEVER been a huge problem for me. So what if a wizard manages to, once in a blue moon, get one over on the fighter with his 18/75 strength? Good on him. Even a 70 pound nerd, with luck, can smack Triple-H down in an arm wrestling contest if he catches the guy off guard.

[Kurald Galain]

It's paradoxical that they're trying to make up rules to cover the actions that aren't covered by the rules.


In my experience, these kinds of actions require a DM to know what the statistics are, because if he adjudicates things arbitrarily without knowing what he's doing, he'll likely make non-covered actions either too easy or too hard.

[Oracle_Hunter]

That's right, it doesn't automatically scale with level, and that's cause you don't suddenly become more dextrous because you gained a level.

Of course, if you felt like it, you could always adjust based on level and say, for instance, that a higher level person who's been doing this kind of stuff for a while gets a bonus to his roll equal to, say, the number of chest hairs he has, but I hardly see the neccessity. Your prowess in battle doesn't improve your balance while pulling stupid stunts.

Plus, ability checks have NEVER been a huge problem for me. So what if a wizard manages to, once in a blue moon, get one over on the fighter with his 18/75 strength? Good on him. Even a 70 pound nerd, with luck, can smack Triple-H down in an arm wrestling contest if he catches the guy off guard.

Then it might be worth noting that there is no way under the rules for any character to get better at balancing. Even if your thief is fluffed as a master acrobat, there is no way he can ever improve his chance at doing a backflip under a straight ability check system. He will have just a good a chance as anyone else with an equivalent DEX score, unless you, as the DM, decide to give him an arbitrary bonus.

There is the main problem with ability checks not scaling, particularly if you want to encourage the PCs to do "stupid stunts." If you do not, ability checks work very well indeed to discourage such things.

EDIT:
@Kurald Galain - that's why 4e is so nice. It does the statistics for you; the DM just needs to arbitrate whether a given stunt is "easy" "medium" or "hard" to do, and whether it does "low" "moderate" or "high" damage; all of these determinations are exactly what a DM should be determining in such a situation.

[Matthew]

There just seems to be an increase in guidelines and examples provided, not really complexity.

1e: come up with a probability that makes sense and is reasonable.

3e: same, with some example numbers and a mention that you may wish to reuse rules for certain events to cover distinct but conceptually similar ones.

4e: same again, but stepping through the idea of calibrating the outcome of successes to what other abilities would let the player achieve at the same level.

Exactly, they are explaining precisely the same process, but with increasingly formalised language and the inclusion of explicit formulae for deriving the probability.

Gosh, Matthew, you are a thread-spawning machine

I like to think I am an interesting thread spawning machine... but only of late.

- An ATRDC should help the DM to convert player input into rules-sensible results. DMs are not privy to the numbers that go into making a game system, and they should not make up such significant numbers if they can avoid it.

This is an interesting point, but not one I agree with. I do not believe the game designers are always better equipped to run the game than the individual game master, and the maths of D&D is pretty simple. Probability theory is pretty simple. All we're doing is assigning descriptive terms to probabilities.

0% Impossible
10% Very Difficult
30% Difficult
50% Medium
70% Easy
90% Very easy
100% Automatic

The formulae are what make things more complicated, and they never ever really work as well as an informed decision about how probable an action is.

- If a DM miscalculates the system numbers, he may produce a new action that invalidates the very purpose of the rules system you are using (e.g. if a Rogue is more effective using an ATRDC sand-throwing attack than using a dagger, why would he ever use the dagger?).

Another good point, and very much along the lines of the "Spring Attack" feat. You can't do X if you need Y to do it. The less rules you have, and the more experience, the less likely this is to happen. Moreover, if the game master ****s somethign up, he can just admit to it, and issue an alternative ruling. No big deal, just the same as over ruling a printed rule.

If you are not using the rules included in the game, why are you playing that system at all?

A slightly different issue, but also a good question. It really depends on how you see "game systems". If you want them to work out of the box, or you want them to be frameworks on which you can build and redesign. AD&D 2e was very much in the latter vein (too much for its own good). There's no real difference between changing the rule for yourself and using an 'optional rule' printed elsewhere, excpet as to who you target with the blame when it doesn't work, and who you praise when it does.

The problem with the ability check is that it didn't scale with level. No matter how much time you spend running on narrow ledges or swinging on chandeliers, you have as good a chance of making the run at 1st level as you do at 20th. This might be OK for a Fighter, but for the Rogue who went from a 50% chance of climbing walls to a 99% chance of doing it in 20 levels, he's going to look pretty silly having never improved his balance.

You just modify the attribute check by level.

Plus, opposed ability checks were always a huge problem. The famous Wizard-Fighter arm-wrestling challenge for one.

Don't use an attribute check for it.

[Caveat] I don't actually like attribute checks. [/caveat]

Remember, DMs are imperfect.

As are rule sets. They are, after all, designed by people who DM for a living.

It's paradoxical that they're trying to make up rules to cover the actions that aren't covered by the rules.

Indeed. We should probably think of these as "specifically covered" and "generally covered" actions.

Then it might be worth noting that there is no way under the rules for any character to get better at balancing. Even if your thief is fluffed as a master acrobat, there is no way he can ever improve his chance at doing a backflip under a straight ability check system. He will have just a good a chance as anyone else with an equivalent DEX score, unless you, as the DM, decide to give him an arbitrary bonus.

There is the main problem with ability checks not scaling, particularly if you want to encourage the PCs to do "stupid stunts." If you do not, ability checks work very well indeed to discourage such things.

We should be careful here. Attribute checks are one way of adjudicating actions. They are only supposed to be used when it makes sense to use them. They also are definitely and explicitly subject to modifiers (based on DM fiat), just as these things are in D20 3e/4e (known as circumstance modifiers or the DM's best friend post 2000)


The eagle eyed amongst you might have noted a distinct lack of an entry for 2e. that's because there isn't any real advice on the subject in the core books (tons in the support books, but none in the core books...). I had the opportunity to ask David Cook about this and he admitted it was an oversight. I have included some of the text from First Quest now, which in about one page provided critical (in my opinion) information missing from the core books. Consider it errata.

[hamlet]

Then it might be worth noting that there is no way under the rules for any character to get better at balancing. Even if your thief is fluffed as a master acrobat, there is no way he can ever improve his chance at doing a backflip under a straight ability check system. He will have just a good a chance as anyone else with an equivalent DEX score, unless you, as the DM, decide to give him an arbitrary bonus.

There is the main problem with ability checks not scaling, particularly if you want to encourage the PCs to do "stupid stunts." If you do not, ability checks work very well indeed to discourage such things.

And I just said that if you feel that he will get better as he advances in experience, then adjust the ability check according to his level or as you see fit.

It ain't rocket science and it's only there to provide a quick and easy method to assign a probability. The more dextrous you are, the more likely you are to be able to pull of some stupid stunt like that.

You can just as easily rule that, because he's a master acrobat, he manages to pull of a backflip with no problem at all. Do you really need a rule to govern whether somebody supposedly trained to do these things is able to do them? Unless of course, he's using a back flip to gain a superior combat advantage, in which case I'd say the ability check still applies and governs whether he was able to gain his superior position rather than succeeding on his flip or not.

And, on top of that, who the hell takes an acrobat into combat anyway? I'll take the ax-crazy lunatic with the crazy eyes over that pansy any day.

[Caveat] I don't actually like attribute checks. [/caveat]

And yet you're the one who convinced me to spend my food budget on the C&C books which rely extensively on attribute checks, though admittedly in an inverted fashion.

[Matthew]

And yet you're the one who convinced me to spend my food budget on the C&C books which rely extensively on attribute checks, though admittedly in an inverted fashion.

Hey, I said I wasn't a fan of attribute checks or the siege system in that thread as well.

Still, I like Castles & Crusades a lot, and their approach to the attribute check is probably one of the best going; as long as they are used in moderation and you are willing to use other task resolution methods when better suited, they work great. For what it's worth, I usually disregard primes and treat humans as having +3 on each attribute, and demi humans as having +2.

Hope C&C is working out for you!

[Jayabalard]

Remember, DMs are imperfect.

So are rule systems; in general though, DM's are far more capable of making rulings that make sense than any paradoxical set of rules to covers situations that aren't covered by the rules.

[DM Raven]

Except that in 4e you actually have to look it all up in tables, instead of making it up on the spot.

You don't actually have to...the issue of "DM Freedom" comes up in that the DM can handle a situation however he sees fit. You could use the 1st, 2nd, 3rd, or 4th edition method for 4th edition. The difference is, in 4e you have more powers that can accomplish the things like, "I want to swing and kick someone into a fire" and the DM will have more tools they can or cannot use to accomplish this. You could say, "Give me an acrobatics check, this happens" for any of the editions.

Again, you are thinking of rules as a boundary that you must stay within, I think of rules as having more tools to work with.

And there are no tables, its actually pretty easy to make an acrobatics check and use the trick strike ability. Or just use a bullrush...

[nagora]

The problem with the ability check is that it didn't scale with level.

Actually, every time I have used ability checks I've allowed the player to subtract their class level from the dice when the class is appropriate.

But, as I said, I've never found a one-size-fits-all task resolution system in any game or homebrew.

And, on top of that, who the hell takes an acrobat into combat anyway?

A mime?

[Kurald Galain]

It struck me that this may be an issue: many things are in fact covered by rules, in the form of powers. And whenever something is covered by a power, the default assumption is that you can't do that unless you have that power. 3E had the same issue, to some extent, with feats.

[MartinHarper]

Yeah, maybe, except that many of us old fogies solve this with a quick mechanic called "the ability check."

As do us new fogies, though we call it an "attribute check". The difference is just that the DM picks an arbitrary modifier instead of setting an arbitrary DC.

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Player1: I want to run up the burning beam and onto the second floor balcony to escape.
DM: Fine, make a Dexterity check, call it DC15 because of the smoke and burning oil on the beam.
Player1: *rolls d20* That's a 12, plus four equals 16. I made it!
DM: Cool. Now the Ghoul Lord on the 2nd floor can melee you.
Player1: Oh . . .
Player2: I want to do the same thing and try to help out my friend!
DM: Same check.
Player2: *rolls d20* Oh no, I got a 10!
DM: You fall off about halfway up the beam. You take d6+1 damage from smashing face first into the floor and are now on fire. You'll take d6+1 ongoing fire damage at the start of your next turn.
Player2: Ouch!
Player1: Oh my god stop eating my eyes! Oh no, it's going to kill me! Help me!
DM: Heh, anybody else want to give it a try?
Remaining Players: Nope, sorry dude, you're on your own. *PC's rush out front door and leave idiots to their fate*

I was specifically talking about nagora's advice of judging each case individually and rolling percentiles. You seem to agree with me by mentioning ability checks as a better alternative.

[Starsinger]

It struck me that this may be an issue: many things are in fact covered by rules, in the form of powers. And whenever something is covered by a power, the default assumption is that you can't do that unless you have that power. 3E had the same issue, to some extent, with feats.

I have to agree. Some of my more, rules dependent players, and by that I mean the people who don't comprehend the idea that they can do things other than what the book allows, had a hard time believing you could bull rush in 4e because Tide of Iron exists.

[MartinHarper]

Whenever something is covered by a power, the default assumption is that you can't do that unless you have that power.

I don't think so. Per the 4e DMG, the default assumption is that the DM says yes. Hopefully the DM communicates that to the players.
The main difference when I DM is that powers are more reliable, quicker in game time, and are normally more powerful than at-will AtRDCs. On the other hand, situational AtRDCs (such as shooting an arrow to drop a chandelier on someone's head) are normally more powerful than at-will powers.

[Tsotha-lanti]

Except that in 4e you actually have to look it all up in tables, instead of making it up on the spot.

Eh wot?

You just make the DC 10 + ½ PC level, +5 if it's medium, +some if it's harder, and there you've got it, pretty much. 2nd-level PC wants to do such-and-such? Oh, I guess you can make a DC 16 Acrobatics check (that's about a 70% chance of success there) and deal, I don't know, 2d6+Dex damage and knock the guy back one square. Nobody can repeat the trick, at least in this combat. (Or today.)

If you understand the rules and the probabilities it's all built on, it's easy to keep relatively balanced.

[Justin_Bacon]

The thing is that a lot of the time, the extra steps in 3e+ are strangely counter-productive. If a character wants to, say, run up a fallen roof beam and jump over the wall into the river, I may think to myself "oh, maybe 30% chance given the smoke, the burning oil on the beam and the fact that they have a Dex of 8". The player then rolls d% and we see what happens.

If I want to translate that into "official" 3e/4e speak, I have to try to work out what DC gives the desired chance for that character. What's the point of that extra calcuation?

The only "point" of the extra calculation is that you like making extra work for yourself. :)

In 3rd Edition, you decide the universal difficulty of the task -- not the difficulty for a particular character. The actual percentage chance of success is determined by the character's skill -- you don't have to think about it at all.

In fact, if we look at this in terms of the actual decision-making process being made here, the 3rd Edition version is considerably easier. In your method you:

(1) Take into consideration the difficulty of the task.
(2) Take into consideration the character's ability.
(3) Determine a percentage chance of success.
(4) Roll the dice.

In 3rd Edition all you need to do is:

(1) Take into consideration the difficulty of the task.
(2) Roll the dice.

This effect is compounded by the totally weird spacing of DCs which give people far too big a range between auto-fail and auto-succeed, which ultimately can be traced back to the original design of the skill system in 1e OA which used a d20 for no good reason. The original designer seems to have thought that using the same die for skills and combat was in some way intuative without considering the effects.

It's downright perverse to argue for using percentile dice to resolve checks and then complain about a d20 having too large a range. How can you not realize that 100 is a larger number than 20?

For example: a single roll of d20+5 has a 25% chance of rolling 20 or more. The chance of rolling 24 or more twice duing a skill challenge is only 6%, and three times is 1.5%. So, the same skill can go from "perfectly decent chance" to "you'd have to be desparate" depending on how the DM applies it. I think this could cause trouble if it wasn't for the fact that I think skill challenges will simply die away and become a forgotten experiment.

You seem to be performing a bait-and-switch there. Yes, there's a significant (20%) difference between a DC 20 task and a DC 24 task. And, yes, making 3-out-of-5 basketball shots from a location is actually more difficult than making just one basketball shot from the same location.

What's your point?

[Oracle_Hunter]

This is an interesting point, but not one I agree with. I do not believe the game designers are always better equipped to run the game than the individual game master, and the maths of D&D is pretty simple. Probability theory is pretty simple. All we're doing is assigning descriptive terms to probabilities.

0% Impossible
10% Very Difficult
30% Difficult
50% Medium
70% Easy
90% Very easy
100% Automatic

The formulae are what make things more complicated, and they never ever really work as well as an informed decision about how probable an action is.

So, here's another thing I think rules should do: provide a basis for players to rationally determine a course of action for their character.

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In a game where character skill is important (which, I maintain, is the case in D&D) the likelihood of success should be heavily determined by the contents of your character sheet - did you train in balancing? Does your armor interfere with the check? How good is your natural balance? What effect does a slippery surface have?

In 1e, few of these modifiers were ever explicitly described, particularly on the player side of the screen. A player wouldn't know, ex ante, whether or not Terry the Thief would view walking on a narrow beam as an easy task or a suicidal one. He would require his DM to first decide how "hard" the check would be (Easy? Medium? Difficult? Very Difficult?) and then to see how the DM weighs the modifiers (OK, Thieves should be good at balancing so +LV, but he's Moderately Encumbered so... -10? Sure. Um, add in his DEX score...) and then, if it sounds like a good chance, try it. These can turn complicated "skill" situations in 1e into a game of "Mother May I" where the player and DM try to hash out how hard various potential actions of his character and settle on one with an appropriate difficulty. If this negotiation is too long, DM & Player may be discouraged from doing ATRDC (putting us back in Nagora's Prison). Or the DM may end up just hefting all the potential modifiers and throwing an ad hoc +/- 10% in whichever way the scales seem to be tilting, and get on with it.

However, if you allow the base rules to encode a lot of these modifiers beforehand, then the player has a better idea as to what kind of tasks his character is good at. Encode an encumbrance/armor penalty into a skill system, and Terry already knows that for all physical checks he has a given penalty - and how valuable dropping some crap might be. Add in ability modifiers and skill modifiers, and the player has enough information on his hands to get a pretty good idea as to what his character is capable of doing.

If we assume that game designers produce better systems than we do (or we would just use our own homebrew system), then a skill resolution system which has modifiers included in it by the game designers will work better than one in which all modifiers are ruled, ad hoc or via homebrew, by the DM. 3e and 4e sought to provide such a system, having calculated what modifier numbers are appropriate to model what in-game constraint. These include a skill system which reflects characters developing non-combat skills which can broadly apply to ATRDC situations, and a tabulation of modifiers that may apply in such situations (being blind, slippery beams, etc.).

Summary
1) Postulate: the people who designed the game system you are playing are better at creating a system of rules than you are. Reason: if you were better at creating a system of rules, you would be using your own homebrew system instead of spending money on their inferior system.

2) Any ATRDC system will require a table of modifiers to reflect character skill. Either the DM makes it up on the spot, or the System can provide it beforehand. A System that provides it beforehand is a boon to players, as they can get a superior ex ante understanding of their character's capabilities.

3) The "informed decision" of the DM typically requires a totaling up of these modifiers in one fashion or another.

If the System provides no guidance, the DM will either have to homebrew up his own list, or make a rough judgment as to the effects of things such as character level, character aptitude, character physical status, atmospheric situations, and physical difficulty. Such a rough judgment will commonly be small, round, bonus/penalty (say, +/- 10%) as those are easy to apply and think up, regardless of the actual severity or relative strengths of these factors.

However, if the System calculates it beforehand, both players and DMs can have a good sense as to their relative weight before the situation arrives. These numbers are unlikely to be a standardized +/- 10%, providing greater granularity to ATRDC checks. Additionally, such checks are more likely to be in line with greater System design philosophies (see Postulate).