This thread is for declaring the ultimate supremacy of your favorite mathematically equivalent resolution system.  Now stop shitting up the RQ6 thread.

roll-over = Rolemaster
roll-under = Runequest

Both are good.

I find roll over more intuitive.

Quote from: CRKrueger;468509This thread is for declaring the ultimate supremacy of your favorite mathematically equivalent resolution system.  Now stop shitting up the RQ6 thread.

I prefer roll under. It makes the chance easy to understand at glance since I deal with percent chance of x happening almost every day. Roll over can be  mathematically equivalent, but it is less intuitive -- at least for me.

I really don't give a fuck whether it's roll-over or roll-under as long as the system works.

Quote from: HombreLoboDomesticado;468514I really don't give a fuck whether it's roll-over or roll-under as long as the system works.

This.

I'm a huge fan of houseruling for the sake of fine-tuning a game.

I'm not a fan of houseruling for the sake of houseruling.

I actually like roll 1d100, add bonuses(skill level) and try to get a target number, like "100"...

Well, the percentile games I've designed are all roll under so I guess that's my preferance.  I love Rolemaster but too many people have trouble doing double digit math.

Mind you, roll between is closer to my favorite though it still breaks down.  Roll under skill roll over difficulty is essentially the same as roll under skill - difficulty and only becomes more complex when difficulty exceeds skill or skill exceeds 100.

Roll over is strictly superior the moment you:

• Have modifiers.
• Have opposed tests.
• Have to calculate degree of success.

If you are literally always applying a pass/fail test against your unmodified skill check, then Roll Under is a little bit easier. The very moment that a circumstantial modifier could change your chances or you'd be asked to compare the amount you succeeded by to another character or to a chart, then Fixed TN 100 is demonstrably the superior option.

In Fixed TN 100 your modifiers and results get added together into a single number, which means that if you forget a modifier or have to compare values that the player only has to report one number. In roll under, you have two different numbers to keep track of (modified skill and roll), or you collapse it into a single number by replacing addition with subtraction that demonstrably takes more time to complete. Either way, TN 100 is faster and better at resolution.

There are basically two ways for Roll Under to generate degree of success. The first is "Blackjack", where the literal number you roll is your degree of success if it is under your TN and a failure if it is not. This has the advantage of being relatively fast, since actual resolution is just a comparison and your degree of success is the unmodified number on the dice. Unfortunately, that bogs down severely when you have skill modifiers, because you have to report and modify your skill number separately from reporting your actual roll and if you forget a modifier you have to remember both the literal roll and the modified skill (since "I missed by 3" is actually meaningless information in such a system). The second way to generate degree of success in roll under is "subtract roll from modified skill". This doesn't have the multi-reporting issue, but the procedure is literally exactly the same as Fixed TN 100 except that it uses subtraction instead of addition, which is a provably slower operation when used by real people at the table.

This isn't a thing where we agree to disagree or where both sides have points. It's mathematically equivalent and Fixed TN 100, Roll High is provably superior. It has the positive qualities of both the Blackjack and Subtraction methods of calculating degree of success. And no additional disadvantages. If you support Roll Under, you are a grognard. You are someone who is willing to use a demonstrably and demonstratedly inferior system just because it was "good enough" in the 1970s. I genuinely feel sorry for people who continue to support d100 Roll-Under.

-Frank

I'm gonna need some examples, there.

Quote from: Vile;468540I'm gonna need some examples, there.

Fair enough.

Let's say you have a skill of 60. Regardless of what you do, the system is going to output that you succeed 60% of the time, because that is what a d100 is for. Also, if you have a -10% modifier, you will succeed 50% of the time. Now there are three ways to get degrees of success out of this:

[size=14]Blackjack[/size]
In the Blackjack system, a roll that is more than your modified skill is a failure, and a roll that is less than your modified skill has a success value equal to the number rolled. This is relatively fast to generate degrees of success, but you have to track and report both the literal roll and your modified skill separately in case you missed something or the GM wants to spring something on you.

So you roll a 59. Your degree of success is "59", unless you have a penalty that lowers your modified skill to less than 59, in which case your roll is a "failure". But you still end up subtracting the roll from the skill to determine whether modifiers would matter, and then you have to track the number of how much you made or failed the roll by and the literal number you rolled separately if you want the ability to retroactively add a modifier. So a 59 is "very good" if your modified skill is 59 or better, and "very bad" if not.

[size=14]Subtraction[/size]
In the subtraction system, your degree of success is the modified skill minus the literal roll on the dice. This has the advantage that a good roll is always good (00 is a degree of success equal to your modified skill). And it has the advantage that it has one reporting number that can be further modified by new modfiers as you think of them. However, a near miss that you're looking for a positive modifier to push over the top is a negative number and in any case the core mechanic is one of subtraction - which is just like addition mathematically but is substantially harder for people to actually do in practice.

In the subtractive system a roll of 59 is always pretty bad, and it gives a result of "1" if you have a skill of 60 and a result of "-9" if you have a -10 penalty at the time.

[size=14]TN 100[/size]
In the TN 100 system, you add the roll to your modified skill. Your target number is 100, and your "degree of success" is simply the actual result (2-digits degrees of success are failures). This has the unity of result and success that Blackjack provides and it has the single reported result that Subtraction does.

In the TN 100 system, you roll a 59 and add 60 and get 119. If you have a -10 penalty you need to add, it goes down to 109. But your numbers stay positive all the time and you don't need to track more than one number for reporting purposes.

-Frank

Quote from: FrankTrollman;468545Let's say you have a skill of 60. Regardless of what you do, the system is going to output that you succeed 60% of the time, because that is what a d100 is for. Also, if you have a -10% modifier, you will succeed 50% of the time. Now there are three ways to get degrees of success out of this:

Two points:

1) In many games, you don't need a get degree of success out of the roll.

2) There's a fourth method. The one Chaosium Runequest (and other BRP-based games use). Special/Impale and critical successes are a percentage of your chance of success -- and are looked up on a table so you don't need to do any math at all to determine them.

Quote from: RandallS;468565Two points:

1) In many games, you don't need a get degree of success out of the roll.

2) There's a fourth method. The one Chaosium Runequest (and other BRP-based games use). Special/Impale and critical successes are a percentage of your chance of success -- and are looked up on a table so you don't need to do any math at all to determine them.

If they are a "percentage of your chance to succeed", that would normally be a form of math. Of course, there are better ways to do that too. For example, rather than dividing your modified skill by 10 (or 5), just assign one number (or 2) in the ones place to be the critical threat. If you got the magic number and you succeeded, it's a crit.

Doing that is just like the roll under "divide your modified skill by X" system except that it is more forgiving if you have a modifier you need to add later (since you never need to "redo" the division because you never had to do any division) and it's faster all the time because you never have to do a division step.

The basic mechanics of most d100 systems are old and clunky and they can be improved without loss of functionality by embracing modern, streamlined mechanics.

-Frank

Okay, if I'm getting this straight, the main difference is that with roll-over you have a fixed target (always 100), while with roll-under the target moves for every situation. Both systems use modifiers. That seems a simplification to me on first reading.

D100 uses degrees of success based on a fraction of the chance. Maths needed if you don't use the table, although you learn the numbers pretty quickly if you game regularly. Roll over would need a similar system to create, say, criticals.

The opposed roll degree of success thing also works pretty much the same with both systems. Basically, the higher successful roll wins.

I can see I'll be looking into this in more detail. It might be worth adopting roll-over in a new game, but not for an established TM that has certain fundamental expectations attached to it. Assuming the roll-over tops roll-under, the difference does not seem to justify changing an established system, either from the (re)writing effort or customer expectation perspective.

Now, a new game ... TNQuest ... TNQ ... TaNQ, a future game of sentient armoured bolos! Are there actually any games out there that use Roll-over D100 (given that I can't stand Rolemaster)?

Quote from: FrankTrollman;468567If they are a "percentage of your chance to succeed", that would normally be a form of math. Of course, there are better ways to do that too. For example, rather than dividing your modified skill by 10 (or 5), just assign one number (or 2) in the ones place to be the critical threat. If you got the magic number and you succeeded, it's a crit.

It me, this is much harder as I have to look at the dice in two different ways: first as a percent, and second to see if some specific number came up on a specific die. With the standard Chaosium RQ method, I read the dice once as a percentage at glance at the table on my character sheet to tell me if I succeeded and how well. I don't think either method is intrinsically better. Which is better for an individual depends more on personal preferences than on anything else.