That was a very good reiteration of your concern.

Now could I have an actual explanation of what you are actually talking about?

Try an example.

Quote from: Opaopajr;659427That was a very good reiteration of your concern.

Now could I have an actual explanation of what you are actually talking about?

Try an example.

er, ok

I want to hack the enemy defence system. The target number is my skill, Hacking: 50%. How do i represent the difficulty of that system?

Quote from: Ghost Whistler;659443er, ok

I want to hack the enemy defence system. The target number is my skill, Hacking: 50%. How do i represent the difficulty of that system?

Bonus or penalty to the target number. +/- 20%, target number is 70 and 30 respectively. The problem is the final TN can be above 100 or below 0, which may or may not be an issue.

Bonus or penalty to the roll, roll dice and add 20 (penalty) or subtract 20 (bonus) to the roll. The problem is the final roll can be above 100 or below 0, which may or may not be an issue.

Blackjack opposed roll, vs. 30 as compared to 70. Rolls and TNs are always in the percentile range, but it may or may not make sense to you to give a roll to a firewall. Or for that matter, to an actual wall if you're trying to climb it.

A rather convoluted one, for added difficulty, some 'ones" digits are auto-fail, for added ease some 'ones' digits are auto-success. 00 is low (an aesthetic choice, I just like double-aught as being a good thing, you could make it high and adjust things accordingly), 99 is high. A normal roll is the straight percentage. A difficult one is given a number rating, and if that number or higher shows up on the "ones" digit, the roll fails. For example, on a difficulty of 9, (09, 19, 29, 39, 49) would also be failures for a TN of 50. On a difficulty of 7, (07-09, 17-19, 27-29, 37-39, 47-49) would fail. On an ease of 0, (60, 70, 80, 90) would succeed. On an ease of 2, (60-62, 70-72, 80-82, 90-92) would succeed. The max ease would be 8 (so 9s above the TN would always be failures), the max difficulty 1 (so 0s below the TN would always succeed). This could be combined with blackjack opposed rolls in some situations. All rolls are within the percentile range, but it takes a while to adjust to, and it isn't quite as fast for reading the dice.

Figure the skill of the opposition, use the resistance table from BRP.  

Roll under, take the difference between your roll and your skill, then compare it to a difficultly bias?  It's worked well enough for my purposes.

1.  Roll
2.  Skill - Roll = Difference
3.  Compare Difference vs. Difficulty

Example 1
Hacking Skill:  50
Difficulty: 20
1.  Roll:  25
2.  50 - 25 = 25
3.  25 vs. 20 = Success!  (Minor Success at that.)

Example 2
Hacking Skill:  50
Difficulty: 20
1.  Roll: 85
2.  50 - 85 = -35
3.  -35 vs 20 = Failure...  (Pretty significant failure.)


The nice thing is the player only has to worry about his or her numbers and relaying them to the GM.  The player doesn't need to know meta-game knowledge like difficulty bias, bonuses, and penalties...  That is strictly GM knowledge.

Basic pass/fail would use a straight modifier:
--roll under Computer Use 50% with -xx% penalty.

Basic degree of success would use a secondary threshold (or randomizer, like crits):
--roll under Comp Use 50% to get in, but for every 10% under you avoid one of three alarm systems (thus -30% for a perfect result).

(Random DoS would be 'the ones place is how many +/- steps away from 5, with 5s being crits' or 'double numbers, like 22, 44, etc. are crits' or things like that.)

Basic contested roll would be GM roll under for CPU defense value and compare:
--roll under Comp Use 50% and find your difference from skill. GM roll CPU xx% and find its difference from skill. Compare differences for who is higher.

Degree of success (and the random crits) can be added to other resolutions as needed.

There's also contiguous rolling, multiple rolls and tally successes against a benchmark. Mechanically it is the same as D&D 4e skill challenges; get more successful rolls before too many unsuccessful rolls. I don't add it in discussions usually as the mechanics got a bad rap from said edition. It's a fine resolution method, but like oregano, a little goes a long way -- use sparingly otherwise dice rolling tedium will occur:
--roll Comp Use 50% and get 4 successes before getting 2 failures. (Again environmental modifiers, DoS, and crits makes this a lot more exciting.)

So, there's your basic resolution systems that apply to just about all dice rolling systems. They may be mixed and matched as necessary to resolve different situations, to be as formalized in core rulebook or not. Does that help?

I use both in a manner of speaking.

For opposed actions, it's considered skill vs skill. I roll 1d20+skill (as attacker), you roll 1d10+skill (as defender) and if i tie with you or total higher then i succeed.

For unopposed actions, it's considered skill vs difficulty. I roll 1d20 under skill-difficulty.

I just ask myself "on a scale from one to ten, ten being extremely difficult, how difficult is this task?" Then i have the player subtract that from their skill and try to roll under the total.

An alternative would be to add the difficulty to the dice roll, rather than subtracting from the skill itself, which might be easier for the GM to hide difficulty ratings, if that were desirable. Just ask them their skill and roll, then you should be able to see relatively quickly whether they succeeded or not.

EDIT: Again, success if tied. However, i do a simple variation of the degree of success model. If i roll a natural success (20 in the case of opposed, 1 in the case of unopposed) then the result is more than favorable, it is quite good and may yield additional benefits (gather information check finds more information that expected, climb wall check discovers an easier path that may benefit party members also attempting to climb the wall, etc.) Any number between the natural success and the tie yield normal results. Ties yield a narrow success (brew potion results are barely effective, diplomatic attempts turn in your favor but the other side now hates your guts, etc.) Anything less than a tie is, of course, a failure.

Roll under skill / roll over difficulty. Mathematically identical to TN penalties, unless your dice are on a bell curve.

Quote from: Ghost Whistler;658082How do you feel about roll under systems that use modifiers (eg Difificult Action -2 to the target number) to simulate difficulty?

I have no problem with them. Many of my favourite systems use similar mechanics, so I am familiar with them.

I'm tinkering with the idea of a roll-under system that implements both the "flip-flop" mechanics used in Warhammer and Unknown Armies and roll-and-keep dice pools. It uses neither additions nor subtractions.

In its most basic form, it has abilities (broad, generic skills, like "subterfuge" or "melee") with ratings ranging from 10 to 90 and "binary" specialties (narrow, specific skills, like "sneaking", "hiding", "sword", "mace"). The latter are "binary" in the sense that you either are specialized in a particular activity, or you don't. In a more advanced (but not necessarily better) form of the system, also specialties have ratings.

When a player has to make an ability check, they roll 2d10, with the "0"s read as zeroes, not as tens. If their character doesn't posses the relevant specialty, they read the high result as the tens' digit, and the low result as the ones' digit; if the character does possess the specialty, they read the low result as the tens' digit, and the high result as the ones' digit.

The two-digit number thusly generated, ranging from 00 to 99, is confronted with the character's ability rating; if the number is equal to, or lower than the rating, the result of the check is a success; otherwise, it is a falure.

If the two-digit number is "matched" (that is, has the same number as the tens' and the ones' digit, e.g. 00, 11, 22 etc.) and is equal to, or lower than the rating, the result of the check is a critical success; on he other hand, if the number is matched and is higher than the rating, the result of the check is a critical failure.

Challenging actions performed in tense situations, like trying to kill an enemy with, or not to be killed by, the wild swing of a sword, are considered "standard" (adventuring) actions. However, characters will often attempt actions that are easier or harder than "standard" actions: whenever easier actions are being attempted, ability checks are made by rolling a varying number of d10s called "bonus dice" (bd), besides the normal 2d10; likewise, whenever harder actions are being attempted, checks are made by rolling a varying number of d10s called "penalty dice" (pd), besides the normal 2d10.

When a player rolls 2d10+nbd, the number they have to confont with their ability rating is generated using the two lowest results rolled on the dice; on the contrary, when a player rolls 2d10+npd, the number is generated using the two highest results rolled on the dice.

Possessing a specialty makes a huge difference: a character that has a rating of 50 in an ability but doesn't possess the relevant specialty, has a chance of success of 26% when attempting a standard action, whereas a character that has the same rating but possesses the specialty has a chance of success of 74%. During play players should therefore generally not be allowed to "buy" their characters new specialties, and should only be allowed to rise their characters' ability ratings. Specialties should be chosen and/or granted by classes/profession at character creation, and seen as a "niche protection" device.

Bonus dice make success and critical success more likely, whereas penalty dice make failure and critical failure more likely.


That's all. Any feedback is most welcome, especially negative feedback that will make me bail out of this idea and make a better use of my free time.

It occurred me that it would also be possible to just have "standard" BRP-like skills rated 10 to 90, with characters specializing in some skills and not in others according to their class/profession...