On smaller bonuses and the d20 mechanic

[Flatus Maximus]

The d20 mechanic boils down to: 1d20+M >= TN, where TN = target number (e.g., AC, save DC) and M = total modifier relevant to the task. Equivalently, 1d20 >= TN-M.

Note that TN-M < 1 is the condition for auto-success, while TN-M > 20 is the condition for auto-fail; in other words, if the outcome is to have any uncertainty, then we must have 1 <= TN-M <= 20. For rolls that are to happen with any regularity, it would seem most fun if TN-M stays within this range.

Also note that TN needs to be relatively large, since otherwise PCs are “good” at the task even with no modifier – players might not feel all that heroic if the task is something that commoners can routinely do. This, in turn, forces M to be relatively large, since otherwise TN-M falls out of the range 1-20.

On a psychological note, the smaller the modifier relative to the size of the die, the less the player may feel that the PC has any impact on the determination of the outcome. (I call this the “heft” of the modifier.) For example, for some (most?) people, rolling 1d20+2 probably doesn’t feel all that different from rolling 1d20, and these folks may not feel that their PC has much influence on the outcome, even when TN-M is very small (that is, even when they are very likely to succeed anyway).

So, for the d20 mechanic, it seems necessary that target numbers must be relatively large, so that PCs, and not just commoners, are required to do the job; as well as modifiers, so that PCs have a chance to succeed with larger target numbers and players feel that they have a noticeable effect on the outcomes of the mechanic.

If the designers of D&Dn are serious about wanting to keep bonuses relatively small, then it would seem that they can’t just reduce the size of the target numbers. The only other parameter remaining that we can tweak is the size of the die. For example, if we replace the d20 with the d10, then target numbers can be considerably smaller, which we have seen, means that bonuses can be considerably smaller. What’s more, the +2 in a 1d10+2 roll is likely to feel more “hefty,” so that the player feels that their PC has more of a significant effect on determining the outcome of the roll. Edit: As a side benefit, the arithmetic is likely to involve only single-digits.

Quite naturally, TN and M should grow with level. However, with 20-30 levels, even with modest growth per level, the difference between low levels and higher levels will be great. With fewer levels and a smaller starting point for TN and M, combined with modest growth, will result in characters that are not so far apart at the extremes of the range of levels. Of course, players expect that the higher level PCs will be clearly superior to the lower level PCs, but perhaps by tweaking these parameters, these two groups of PCs can still campaign together.

OK, getting kinda long so I'll stop there. Not sure what else I had to say anyway.

 

[BobTheNob]

The psycological aspect you mention is the key to why numbers have kept going up (I will focus on BAB as it has modelled growth since growth since 2e) with levels.

It took alot of soul searching with 3e till I realized that dynamic growth can break things so easily.

I am all for flattening out number growth altogether and making level advancement more about attaining new abilities rather than bigger numbers. It lends itself better to multiclassing and avoids "bell curve" probability as you never get that close to the dreaded 1-3, 18-20 ranges. But most importantly, more abilities gives a greater "heroic" feel to everything in that (for instance) your increasing ability with your sword is modelled as cooler abilities rather than just a bigger number.

Again, this is preference. Some prefer number growth for levelling, and thats fine.

 

[Astrosicebear]

I dont think at this point we can expect any change in the base use of the d20. I think that is D&D. Moving to a d10 or d6 would feel too much like other systems. Also, I think the inherent spread of the d20 is beneficial to the randomness of the game.

Now the designers have said that they are limiting the amount of ability score inflation, and since most skills are now ability score based, we will see lower TN values (DC's etc) and lower modifiers overall.

Personally, I like this. While I do indeed like to see my attack roll as +32, and my AC as a number in the 20's or 40's sometimes, I do not like to use a calculator to determine all my rolls. Lowering the modifiers across the board will speed up gameplay greatly.

 

[Crazy Jerome]

If the designers of D&Dn are serious about wanting to keep bonuses relatively small, then it would seem that they can’t just reduce the size of the target numbers. The only other parameter remaining that we can tweak is the size of the die...

You are more or less correct, but this part is where more options are possible. That is, it is true that there is no other parameter to tweak, but you can change the scope of the task, the nature of success/failure, and a whole host of other options.

For example, you allow multiple rolls of the d20 for competent characters. Some people even feel that this more accurately models competence, as the upper end of what the character can do doesn't move very much (with that small modifier) but their success becomes much more reliable.

Or you can provide fate points or other such means for conditional and/or "post roll" mods (or rerolls) or reduction of the DC--to give that feeling of control back. My 1d20+2 versus DC 16 may not be all that impressive compared to Joe Schlub with his 1d20+0, but if I can manipulate the situation with some other resource, then you retrieve both the feel of control and statistical likelihood of success. (It appears in the little we have so far, that skills may fill part of this role in 5E, though they will have a straight mod effect as well.)

That doesn't even get into powers, skills, abilities, magic, etc. that can be used to nullify the need for a roll in the first place and/or radically change what the roll does for you. Think spider climb versus a normal climb.

 

[Crazy Jerome]

There is also a sense in which the big modifiers crowd out all the other, more interesting options. Somewhat the opposite angle that we have all discussed thus far. If you have a +37 to your Diplomacy roll, why do you even care about a magic diplomat hat or a small boost to your charisma or a clever discussion angle or anything else small?

This is hardly a fixed line, of course, especially in a 3E-style game where that +37 is often made up of a lot of smaller, stackable things. But even in 3.* carried to unreasonable extremes, you hit this kind of diminishing return. So there does seem to be a sliding scale, where the closer you get to the smaller mods, the more players will care about all the other means to influence the action.

 

[Jeff Carlsen]

The linearity of the d20 mechanic has always been a little awkward. +2 to a roll feels small, because the range for the die is 1-20. But, mechanically, a +2 versus a DC 15 is identical to +22 versus a DC of 35.

Basically, we shouldn't be comparing the bonus to the die, but to the DC. Since we rarely know the DC as players, it's difficult to do so.

Another way of looking at bonuses isn't as a d20 + Modifier, but as an average of 10 + Modifier. Thus, a +2 is an average skill of 12.

 

[SlyDoubt]

Well you could just add sort of like landmarks in your leveling. Maybe every 5 levels you get to increase skills instead of every level.

But at every level you gain a feat or some other kind of ability or option. Ability scores maybe never change except magically. Maybe base attack bonus or something like it also only goes up every 5.

I think it's more to do with the way leveling is worked out than the math of the d20.

 

[Majoru Oakheart]

What they can do is keep the modifiers very small. Yes, that will alienate some people who will feel that the difference between a 1st level character and a 20th level character is way too small when the difference in their attack rolls is +5, but I think the tradeoff is worth it.

 

[Flatus Maximus]

The linearity of the d20 mechanic has always been a little awkward. +2 to a roll feels small, because the range for the die is 1-20. But, mechanically, a +2 versus a DC 15 is identical to +22 versus a DC of 35.

Basically, we shouldn't be comparing the bonus to the die, but to the DC. Since we rarely know the DC as players, it's difficult to do so.

Another way of looking at bonuses isn't as a d20 + Modifier, but as an average of 10 + Modifier. Thus, a +2 is an average skill of 12.

The reason I subtracted M over to the other side of the inequality is because as far as the probability of success goes, what's important is not M but TN-M. However, a +2 still feels small even if the TN is easily reached. This is the problem with feeling like a commoner that I mentioned above. 1d20+2 vs a DC 5 is overwhelmingly likely to succeed, but so is 1d20. In fact, one could complain that one's character's effect on the outcome is minimal...even though they are likely to succeed.

So it's both the size of the modifier (relative to the size of the die) as well as the difference TN-N (effectively probability of success).

 

[Flatus Maximus]

What they can do is keep the modifiers very small. Yes, that will alienate some people who will feel that the difference between a 1st level character and a 20th level character is way too small when the difference in their attack rolls is +5, but I think the tradeoff is worth it.

Small modifiers mean small target numbers (otherwise chances of success are too small), and, when using the d20, create a feeling that the character's effect on the outcome isn't adequately reflected in the game mechanic. Would you be happy with those implications?