D&D 5E Modifiers, Bounded Accuracy, and Saving Throws

[Riley37]

The thread "Vrax the Rock Thrower" raises some questions specific to Ability Checks (please add your $.02 there on anything *specific to ability checks*). A post in that thread inspired some questions about Saving Throws.

Here's a list of things which modify ability checks and/or attack rolls and/or saving throws. Yes, there are lots of modifiers to attack rolls which are not listed here, such as cover, etc. I hope you'll see my intent, though. What have I missed?

Bardic Inspiration: Ability Check, Attack Roll, Saving Throw, only bonus, only the recipient of Inspiration
(the bard decides, on the bard's turn, to give Inspiration, and then the recipient decides when to use that Inspiration)
Cutting Words: Ability Check, Attack Roll, *Damage Roll*, only as penalty, only on other
Peerless Skill: Ability Check, only bonus, only self

Bend Luck: Ability Check, Attack Roll, Saving Throw, only other, bonus or penalty, d4
Dark One's Own Luck: Ability Check, Saving Throw, only self, only bonus, d10

Bless: Attack Roll, Saving Throw, self and/or others, only bonus, spell, d4
Guidance: Ability Check, self or other, only bonus, spell, d4
Resistance: Saving Throw, self or other, only bonus, spell, d4
(Spells are subject to the "Combining Magical Effects" rule on page 205.)

Lucky halfling racial trait: Ability Check, Attack Roll, Saving Throw, only self, re-rolls a 1.
* This interacts non-problematically with Advantage/Disadvantage.

Lucky feat: Ability Check, Attack Roll, Saving Throw, only self; also, attack rolls by others against you. (PHB p.167)
* If you have Advantage and apply a luck point, then you roll three d20s and take the best one. If you have Disadvantage, do you really get to pick the best of three rolls? is there Order of Operations? Shortcut ruling: rocks fall, everyone dies.

Portent: Ability Check, Attack Roll, Saving Throw; self or other; substitute a pre-determined d20 roll.
(Portent is a Wizard tradition ability, School of Divination, page 116.)
* What happens if you apply Portent to a roll made with adv/dis; does it replace both rolls? If your Portent rolls are 1 and 8, and you're casting at a halfling, and you apply the 1 to the halfing's saving throw, does the halfling then get a re-roll from its Lucky racial trait? Do you use your 8, just to avoid the shortcut ruling?

Scenario: Boris the Druid casts Resistance on William the Warlock (and maintains concentration). Betty the Bard gives Bardic Inspiration to William. Paul the Paladin casts Bless on Doris, William and himself. Carol the Cleric casts Bless on Doris, William and herself. Carol maintains concentration on Bless, and therefore cannot also cast Resistance.

Susan the Sorcerer casts Burning Hands, in a cone which includes Carol, Doris and William. Susan is level 20, and has Charisma 20, so the saving throw DC is 8+stat+proficiency, or 8+6+10, total 24. (PHB page 205, Saving Throws, refers to "any special modifiers". What are some examples of special modifiers?)

Carol rolls a d20 for saving throw, gets 11, rolls d4 for her Bless, gets 1, total 12. Also, she has no proficiency with DEX saves, and has DEX 10, for +0. Uh oh.

Doris rolls a d20 for saving throw, gets 11. Doris rolls a d4 for Carol's Bless and a d4 for Paul's Bless, gets 2 and 3, takes the 3. Doris's saving throw is 11+3=14, before stat and proficiency modifiers.

William rolls a d20 for saving throw, gets 11. William rolls a d4 for Carol's Bless and a d4 for Paul's Bless, gets 2 and 3, takes the 3. William applies his Bardic Inspiration from Betty, rolls d8, gets 4. William rolls d4 for Resistance (from Doris), gets 1 (darn). William rolls d10 for Dark One's Own Luck, gets 2 (double darn). William's roll is 11+3+4+1+2, or 21, before stat and proficiency modifiers.

But wait, it's not over! Susan uses Bend Luck, and rolls d4, getting 4, for -4 to William's saving throw; now it's down to 21.

Some minerals might say that none of these modifiers stack, and that only the highest die applies. Is that the 4 from Bardic Inspiration or the roll of 4 on the Bend Luck die? If the former, then 11+4=15. If the latter, then Bend Luck overrides the Bless, Resistance, Bardic Inspiration and Dark One's Own Luck rolls, and Doris and William both have saving throw of 11-4=7 (before stat/proficiency). If only the highest bonus AND the highest penalty apply, then in this case they cancel each other. (Though if the Bardic Inspiration had been 12, and the Bend Luck still 4, that would work out to a net +8.)

Fortunately, Betty is a Lore Bard, has another use of Bardic Inspiration, and uses her Reaction on Cutting Words, rolling 7 and thus subtracting 7 from Susan's damage roll. NB this is the only ability listed so far which can apply to damage rolls, *as well as* to d20 success rolls.

Bob the Bard, also College of Lore, suddenly appears in the scenario, using a Bardic Inspiration (and his Reaction) to apply Cutting Words to Susan's damage roll, rolling 9. Does his roll replace Betty's roll? Or does he subtract another 9 HP from the damage? (Could a sufficient crowd of Lore Bards, each using Cutting Words - at their annual celebrity roast fundraiser, perhaps - negate all the damage from a Meteor Swarm?)

 

[sithramir]

Can you have 2 bless spells up? You would take the best of either if so but seems it just shouldn't be able to happen.

Like casting mage armour twice. No additional bonus but can it be cast twice on same person?

 

[Dausuul]

Just a suggestion, but when you put forward an example to illustrate your questions, it works better if you limit the details to what's relevant to the questions. I ended up skimming your post looking for question marks to figure out what you were asking.

If you have Advantage and apply a luck point, then you roll three d20s and take the best one. If you have Disadvantage, do you really get to pick the best of three rolls? is there Order of Operations?

According to the Luck feat, you make your regular roll first. Upon seeing the roll, you may then choose to spend a luck point and roll another d20, then pick your preferred result.

As I read it, this means if you have advantage or disadvantage, it applies to the initial roll as normal. So, if you have disadvantage, you roll twice and pick the worst result. That is your Regular Roll. You may then choose to spend a luck point and roll a third time; you take the better of your Regular Roll and the new roll.

What happens if you apply Portent to a roll made with adv/dis; does it replace both rolls?

Portent says, "You can replace any attack roll, saving throw, or ability check [snip] with one of these rolls..." So I would say yes, the Portent replaces both rolls--you don't roll at all.

If your Portent rolls are 1 and 8, and you're casting at a halfling, and you apply the 1 to the halfing's saving throw, does the halfling then get a re-roll from its Lucky racial trait?

That's a tough one, with no obvious answer. I would be inclined to rule the halfling does get to re-roll the 1, but you could argue either way (the halfling did not actually roll a 1, after all; somebody else rolled it and gave it to her).

What are some examples of special modifiers?

I'm not aware of any offhand. Maybe other people can think of some, though.

William rolls a d4 for Carol's Bless and a d4 for Paul's Bless, gets 2 and 3, takes the 3.

This one isn't a question, but it jumped out at me as a mistake: William only gets to roll once. If his first roll is a 2, that's what he's got. The rule on combining magical effects specifically uses bless as an example: You get the spell's benefit only once, meaning you roll one d4 and that's it. You do not get to roll two bonus dice.

Some minerals might say that none of these modifiers stack, and that only the highest die applies. Is that the 4 from Bardic Inspiration or the roll of 4 on the Bend Luck die?

I'd say all of those modifiers stack, so the question is moot. The only case where the mods don't stack is if they're from the same spell.

Bob the Bard, also College of Lore, suddenly appears in the scenario, using a Bardic Inspiration (and his Reaction) to apply Cutting Words to Susan's damage roll, rolling 9. Does his roll replace Betty's roll? Or does he subtract another 9 HP from the damage?

Technically, Cutting Words is not a spell and therefore can stack with itself, so subtract another 9. However, it'd make sense to treat it like a spell and say you can only do it once on a given roll.

 

[Riley37]

The rule on combining magical effects specifically uses bless as an example: You get the spell's benefit only once, meaning you roll one d4 and that's it. You do not get to roll two bonus dice.

Ah, so it does. Thanks.

So when do multiple castings of a spell have a "most potent effect", such as a highest bonus, on a target? That could happen when a spell was "overcast" from a higher-level slot, eg one person casts Aid with an L2 slot, and someone else casts Aid on the same recipient with an L3 slot; is that the only way for a spell to have a "most potent effect"?

On a tangent, if three people were each willing to cast and maintain Enhance Ability on you, could you simultaneously have cat's grace, bear's endurance and bull's strength?

 

[the Jester]

The thread "Vrax the Rock Thrower" raises some questions specific to Ability Checks (please add your $.02 there on anything *specific to ability checks*). A post in that thread inspired some questions about Saving Throws.

Here's a list of things which modify ability checks and/or attack rolls and/or saving throws. Yes, there are lots of modifiers to attack rolls which are not listed here, such as cover, etc. I hope you'll see my intent, though. What have I missed?

Bardic Inspiration: Ability Check, Attack Roll, Saving Throw, only bonus, only the recipient of Inspiration
(the bard decides, on the bard's turn, to give Inspiration, and then the recipient decides when to use that Inspiration)
Cutting Words: Ability Check, Attack Roll, *Damage Roll*, only as penalty, only on other
Peerless Skill: Ability Check, only bonus, only self

Bend Luck: Ability Check, Attack Roll, Saving Throw, only other, bonus or penalty, d4
Dark One's Own Luck: Ability Check, Saving Throw, only self, only bonus, d10

Bless: Attack Roll, Saving Throw, self and/or others, only bonus, spell, d4
Guidance: Ability Check, self or other, only bonus, spell, d4
Resistance: Saving Throw, self or other, only bonus, spell, d4
(Spells are subject to the "Combining Magical Effects" rule on page 205.)

Lucky halfling racial trait: Ability Check, Attack Roll, Saving Throw, only self, re-rolls a 1.
* This interacts non-problematically with Advantage/Disadvantage.

Lucky feat: Ability Check, Attack Roll, Saving Throw, only self; also, attack rolls by others against you. (PHB p.167)
* If you have Advantage and apply a luck point, then you roll three d20s and take the best one. If you have Disadvantage, do you really get to pick the best of three rolls? is there Order of Operations? Shortcut ruling: rocks fall, everyone dies.

Portent: Ability Check, Attack Roll, Saving Throw; self or other; substitute a pre-determined d20 roll.
(Portent is a Wizard tradition ability, School of Divination, page 116.)
* What happens if you apply Portent to a roll made with adv/dis; does it replace both rolls? If your Portent rolls are 1 and 8, and you're casting at a halfling, and you apply the 1 to the halfing's saving throw, does the halfling then get a re-roll from its Lucky racial trait? Do you use your 8, just to avoid the shortcut ruling?

Scenario: Boris the Druid casts Resistance on William the Warlock (and maintains concentration). Betty the Bard gives Bardic Inspiration to William. Paul the Paladin casts Bless on Doris, William and himself. Carol the Cleric casts Bless on Doris, William and herself. Carol maintains concentration on Bless, and therefore cannot also cast Resistance.

Susan the Sorcerer casts Burning Hands, in a cone which includes Carol, Doris and William. Susan is level 20, and has Charisma 20, so the saving throw DC is 8+stat+proficiency, or 8+6+10, total 24. (PHB page 205, Saving Throws, refers to "any special modifiers". What are some examples of special modifiers?)

Carol rolls a d20 for saving throw, gets 11, rolls d4 for her Bless, gets 1, total 12. Also, she has no proficiency with DEX saves, and has DEX 10, for +0. Uh oh.

Doris rolls a d20 for saving throw, gets 11. Doris rolls a d4 for Carol's Bless and a d4 for Paul's Bless, gets 2 and 3, takes the 3. Doris's saving throw is 11+3=14, before stat and proficiency modifiers.

William rolls a d20 for saving throw, gets 11. William rolls a d4 for Carol's Bless and a d4 for Paul's Bless, gets 2 and 3, takes the 3. William applies his Bardic Inspiration from Betty, rolls d8, gets 4. William rolls d4 for Resistance (from Doris), gets 1 (darn). William rolls d10 for Dark One's Own Luck, gets 2 (double darn). William's roll is 11+3+4+1+2, or 21, before stat and proficiency modifiers.

But wait, it's not over! Susan uses Bend Luck, and rolls d4, getting 4, for -4 to William's saving throw; now it's down to 21.

Some minerals might say that none of these modifiers stack, and that only the highest die applies. Is that the 4 from Bardic Inspiration or the roll of 4 on the Bend Luck die? If the former, then 11+4=15. If the latter, then Bend Luck overrides the Bless, Resistance, Bardic Inspiration and Dark One's Own Luck rolls, and Doris and William both have saving throw of 11-4=7 (before stat/proficiency). If only the highest bonus AND the highest penalty apply, then in this case they cancel each other. (Though if the Bardic Inspiration had been 12, and the Bend Luck still 4, that would work out to a net +8.)

Fortunately, Betty is a Lore Bard, has another use of Bardic Inspiration, and uses her Reaction on Cutting Words, rolling 7 and thus subtracting 7 from Susan's damage roll. NB this is the only ability listed so far which can apply to damage rolls, *as well as* to d20 success rolls.

Bob the Bard, also College of Lore, suddenly appears in the scenario, using a Bardic Inspiration (and his Reaction) to apply Cutting Words to Susan's damage roll, rolling 9. Does his roll replace Betty's roll? Or does he subtract another 9 HP from the damage? (Could a sufficient crowd of Lore Bards, each using Cutting Words - at their annual celebrity roast fundraiser, perhaps - negate all the damage from a Meteor Swarm?)

EDIT: Rereading my post, I sounded kind of jerky, sorry. That wasn't my intent. I'd like to help, but there's too much to wade through and I'm not clear on what you're actually asking here.

In general, the same effect doesn't stack, it overlaps. Different effects do stack. Does that help?

If not, could you re-post your question without all the extraneous stuff, so it's a bit more clear?

 

[DaveDash]

When talking about RAW, one thing that DOES stack in terms of saving throws are Paladins auras. So two Paladins with 20 Charsima could give you a +10 bonus to all saving throws.

Most DM's probably wouldn't allow them to stack though.

 

[the Jester]

When talking about RAW, one thing that DOES stack in terms of saving throws are Paladins auras. So two Paladins with 20 Charsima could give you a +10 bonus to all saving throws.

How do you figure? I don't see that called out anywhere (though I admit that the stacking rules in the PH only seem to call out spells).

 

[DaveDash]

How do you figure? I don't see that called out anywhere (though I admit that the stacking rules in the PH only seem to call out spells).

That's how I figure.

It doesn't explicitly say they do not stack - so in other words they do. However most DM's (myself included) would probably rule that it's a magical effect similar to a spell and doesn't stack. If you're theorycrafting though like Riley is then that's another matter.

 

[Li Shenron]

It doesn't explicitly say they do not stack - so in other words they do.

Given the quantistic nature of 5e, I rather think that if the rules don't explicitly say the don't stack, then neither they stack nor they don't stack.

Each DM has to consider what will happen on both the PC and NPC side, if stacking is allowed or disallowed, and rule according to their preference.

For instance, stacking 2 identical effects on the PC side means that a very few PC groups (only those rare groups which have 2 PCs capable of producing the same effect) will very often benefit from the stacking (because it can be used potentially as a regular tactic); while on the NPC side this is totally under DM's control (e.g. the DM is free to decide how often a monster/NPC will have 2 or more supporters stacking this effect on it before an encounter).

Choosing not to stack is probably always the safest choice for a DM who is worried about balance. Choosing to stack is for the DM who is willing to see some more wacky situations, but also capable of counter-balancing them on the longer term with flexible encounter design.

 

[Quartz]

An alternative, as discussed in the other thread, is that one uses the Luck feat as a precedent and that they all cancel each other out. Indeed, where opposing modifiers are involved one could also use the Advantage / Disadvantage system as a precedent to make the same case.

For me, I don't want to get into 3E stack city.