What are your thoughts on roll-under/roll-high mechanics?

[Thomas Shey]

You engage with it the same way you do with a check in D&D, which is to say generally not unless there's some external mechanic that lets you do it (e.g. in D&D you have things like Bardic Inspiration that lets you retroactively mess with a roll). Some games that use Blackjack rolls do have ways of interacting with it – for example, the Troubleshooters (which uses a d100 version) lets you spend 2 Story Points to flip the d100 (read tens as ones and vice versa), but that's not inherent to the Blackjack roll mechanic itself.

Eclipse Phase does this with its Pools, too.

 

[Bill Zebub]

Sure. But the reaction is the reaction, at least initially. Which you can argue is the case with the roll low thing too, of course, but in my experience the intuitive quality overcomes that faster if someone hasn't been in the roll-high sphere for too long.

Yeah and really that's the only point I was making. I'm not arguing for "lower is better" ability scores; just pointing out the similarity with dice rolling.

 

[Thomas Shey]

Yeah and really that's the only point I was making. I'm not arguing for "lower is better" ability scores; just pointing out the similarity with dice rolling.

I don't think they're quite parallel even a neutral standpoint though; while high-is-good is somewhat baked into general our overall expectations, you have to have a sense of what a skill means for any roll with it to make sense, so I'm not sure high-is-good actually trumps land-within there. I'm not sure there's any good way to say one way or another, though.

 

[GMMichael]

You want to roll equal to or under your Attribute or skill. But, within that metric, you want to roll as high as possible. So, if your Dexterity is 13, you want to roll equal to or under 13, with a 13 being the best-case scenario. It has been referred to as a Blackjack-adjacent mechanic. What I like about it is that roll-under is very easy to understand, and the roll-high aspect of it gives characters of higher skill the potential to reach levels of success that other characters can't. And there is no pesky math, for those who don't like adding modifiers.

Nothing wrong with this, but it doesn't follow K.I.S.S. If there are no modifiers, how do you roll for tasks with higher difficulty? If you roll opposed, does the player who rolled her exact score beat the one who rolled higher, but didn't max the roll? Is there still a target number, so the player has two ways to fail (roll higher than attribute or lower than target)? Isn't roll under simpler than roll equal to or under?

This reminds me of why I hate rolling for initiative. say a PC has a +8 Initiative bonus and their opponent has no bonus. The player & GM roll initiative & the GM rolls better simply because the dice say so. It nullifies the fact that the PC has a much better bonus and should go first normally.

What if the PC with a +8 gets a static result? The GM would win less without the PC's chance of rolling low.

 

[Theory of Games]

What if the PC with a +8 gets a static result? The GM would win less without the PC's chance of rolling low.

No. I'm talking about running initiative like GURPS: highest stat or stat + modifier wins. No rolls. This means the fastest (reaction-time) always goes first.

 

[Mark Craddock]

This reminds me of why I hate rolling for initiative. say a PC has a +8 Initiative bonus and their opponent has no bonus. The player & GM roll initiative & the GM rolls better simply because the dice say so. It nullifies the fact that the PC has a much better bonus and should go first normally.

The 'Speedster' superhero should always get the drop on everyone else. The 'legendary gunslinger' PC should always outdraw his opponent. I'm not knocking dice rolls, but they should never negate a character's special abilities.

If the purpose is to BOTH roll under a stat and roll as close to the stat as possible, that's putting the great majority of task resolution on dice rolls, rather than the capabilities of the characters. This is why trad d20 is so popular: it helps characters shine, especially when they gain bigger bonuses from advancement and equipment.

I think the type of dice resolution used is a factor, too, though. GURPS & HERO 's bell curve spotlight skill in a better way. A d20 is pretty swingy too so that should factor as well, right?

I've been playing with a DM assigned difficulty but as a percentage chance. So the DC would be 40% and then you would apply the PC's skill level, say its +20% your final DC would be 60%.

 

[Mark Craddock]

Nothing wrong with this, but it doesn't follow K.I.S.S. If there are no modifiers, how do you roll for tasks with higher difficulty? If you roll opposed, does the player who rolled her exact score beat the one who rolled higher, but didn't max the roll? Is there still a target number, so the player has two ways to fail (roll higher than attribute or lower than target)? Isn't roll under simpler than roll equal to or under?


What if the PC with a +8 gets a static result? The GM would win less without the PC's chance of rolling low.

In a blackjack system, the DM might assign a modifer to the skill level or say you have to roll above X but still below your skill level. Assuming its a d20 roll and you are rolling a skill with a 12 or less, the DM could say you are have a -4 to the roll or could say you have to roll a 4 or higher AND less than a 12. In an opposed situation the winner is whoever rolls under the their skill but has has the highest successful result. So I I have that skill of 12 and I roll a 6, but my opponent has a skill of 10 but rolls an 8, they win.

 

[Thomas Shey]

In a blackjack system, the DM might assign a modifer to the skill level or say you have to roll above X but still below your skill level. Assuming its a d20 roll and you are rolling a skill with a 12 or less, the DM could say you are have a -4 to the roll or could say you have to roll a 4 or higher AND less than a 12. In an opposed situation the winner is whoever rolls under the their skill but has has the highest successful result. So I I have that skill of 12 and I roll a 6, but my opponent has a skill of 10 but rolls an 8, they win.

In fact, in the two blackjack percentile-roll-low systems I know (Mythras and Eclipse Phase) assigning skill modifiers is pretty common.

 

[GMMichael]

In a blackjack system, the DM might assign a modifer to the skill level or say you have to roll above X but still below your skill level. Assuming its a d20 roll and you are rolling a skill with a 12 or less, the DM could say you are have a -4 to the roll or could say you have to roll a 4 or higher AND less than a 12. In an opposed situation the winner is whoever rolls under the their skill but has has the highest successful result. So I I have that skill of 12 and I roll a 6, but my opponent has a skill of 10 but rolls an 8, they win.

Sure, but OP said, "and there is no pesky math, for those who don't like adding modifiers."

And hitting your exact ability score doesn't seem quite so cool when another character can beat you by one point without even getting close to his.