How to know when to call for an ability check vs. a saving throw?

[Greywander]

A lot of the existing mechanics tell you which one to use, for example, X spell will call for Y saving throw or Z ability check. But a big part of TTRPGs is improvising things that are outside the rules. The ability check system made with this in mind, making it easy to figure out what you need to roll to resolve a task not covered in the rules. But how does the DM know whether to call for an ability check or a saving throw? It isn't really clear what the distinction is, or why one is used over the other.

Why do Fireball spells and traps use DEX saves instead of Acrobatics checks? Why does grappling use Athletics checks instead of STR saves? If I down a pint of really strong alcohol, is that a CON check or a CON save?

I guess what I'm asking is if we can't just axe both attack rolls and saving throws, converting everything to run off of ability checks? Do we still need saving throws? What purpose do they serve that can't be fulfilled by an ability check?

[JNAProductions]

They’re more tightly controlled on the math side of it.
And they’re purely reactive. Ability checks are active.

[bid]

I guess what I'm asking is if we can't just axe both attack rolls and saving throws, converting everything to run off of ability checks? Do we still need saving throws? What purpose do they serve that can't be fulfilled by an ability check?

Numenera does that.

Player attacks, player is attacked, player resists frostbites.
It's always rolled by the player and fails when 1d20 below target number.

[KorvinStarmast]

I guess what I'm asking is if we can't just axe both attack rolls and saving throws, converting everything to run off of ability checks? Do we still need saving throws? What purpose do they serve that can't be fulfilled by an ability check?

I don't understand why you want to change this game into a different one.
JNA productions makes a great point: saving throws are reactive to something happening. (Stimulus, response)
Ability checks can be passive or active, but the key point is that they are not necessarily contingent on something else happening. I can decide that I want to pick that lock or try to break down that door, to use two mundane examples, or to grapple that opposing Priest NPC. In play, ability checks are far more flexible than saving throws.
That flexibility, particularly as a tool for the DM, is a plus, not a minus, in play.

With the above said, one of the parts about using illusions is that it gets clunky for a lot of players and DMs is that a PC or NPC has to use an action to attempt an ability check to disbelieve the illusion, or otherwise render it moot. As an example, major image.

A creature that uses its action to examine the image can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC

With phantasmal force, on the other hand, there is a saving throw to get inside the creature's head (so that damage can be done) and there is also the ability check (which costs an action) option that can render it null and void. I have found the spell to be Fiddly as hell in play.

@bid: thanks for the Numenera example.

[Unoriginal]

A functioning, if imperfect mnemonic trick:

A save is when you save yourself from what is done to you.

An ability check is when you are able to do something about it.

[sithlordnergal]

I guess what I'm asking is if we can't just axe both attack rolls and saving throws, converting everything to run off of ability checks? Do we still need saving throws? What purpose do they serve that can't be fulfilled by an ability check?

As people have pointed out Ability Checks are Active or Passive, while Saves are Reactive. However there are two other reasons for Saves to be used over Ability checks:

1) Saves tend to be lower than Ability Checks. Its generally pretty easy to boost an ability check without outside assistance, the same isn't true for Saves. There's no such thing as Expertise for a Saving Throw, unless you count the Paladin's Aura that lets them add their Charisma Mod to their Charisma Save twice. Same goes for Advantage, there are a lot more ways to grant Advantage on a Check then there is on a Save


2) Ease of design and play. Its a lot easier to design Spells and Abilities that use the Save system over using the Ability Check system. And its because there are only 6 Saves that a Spell/Ability can target, as compared to the 18 base skills on a Character Sheet. Not only that, but each Save is tied directly to a corresponding Ability Score, so they're pretty balanced between each other. If I want to make a Spell like Fireball, I, as the designer, know exactly that Save to call for, Dexterity, and its easy on the players too since there's only one Save for Dexterity.

Meanwhile Skills are kind of all over the place. On the physical side, three skills use Dexterity, one uses Strength, and zero use Constitution. On the mental side, there are five Int skills, five Wis skills, and four Charisma skills. So uh, what skills do we use to replace each save. Fireball is pretty easy, obviously that's an Acrobatics check. But how about Slow? Toll of the Dead? Charm Person? Fear? Command? Dissonant Whispers? Scatter? Polymorph? These are all Wisdom Saves right now, and they run the gamut from controlling a target's action, to applying a Condition or Debuff, to Teleportation and changing a creature's physical form.

You would need to go through every single Spell and Ability in the game and decide "Is X spell a Y ability check"? Now, you could just do a blanket check, like all those spells I listed are just Wisdom Checks, and Fireball is just a Dexterity Check. But then what about Proficiency? Are you going to give each class their own little list of Abilities they're just Proficient in? And if you do, does that apply to all Skills made with that Ability? Or will it be separate? If its not separate, and you just give blanket Ability Score Proficiency, then that means all Rogues can be proficient with all Dex Skills. If it is separate, isn't that just the Save system we already have?

[Anymage]

To answer more generally, attacks and saves make it a lot clearer when different bonuses apply. Skill checks (meaning ability checks modified by one of the listed skill proficiencies) are a lot more up in the air, and general purpose skill checks are often even more open ended than that. In extremis, ability checks can be "roll the relevant stat, and add proficiency if you can justify how your character's background or archetype justifies it".

d20 + stat + proficiency if you can justify it can work as a combat engine, but it'll be very freeform, demand a lot of stunting, and most likely spark the occasional argument as to whether the player's justification makes sense. It can work as a very simplified and much more rules light version of D&D, but I have a feeling that "rules light 5e-like" is going to be a very niche product.

[Diovid]

If I were to want to simplify the way abilities interact with Saves, Checks and Attacks I'd go a different route than removing the difference between the three (or between two of the three).

I'd simply remove the difference between score and modifier. Or rather I'd make your modifier your score. You no longer have a Strength score of 8, you have a Strength score of -1.

This would simplify things while still being almost completely compatible with the mechanics and balance of 5th edition. There are a few cases where a uneven score matters (especially when it comes to Strength and when it comes to prerequisites) but those are easily adapted. The only real challenge I see is half feats.

[Kane0]

I don't understand why you want to change this game into a different one.

My guess is that Grey is dipping the proverbial toe into game design but hasnt stretched beyond D&D as yet. These topics are helpful to figure out what can be done based on what has been in the past, and also gauge how D&D players might respond to such things placed in front of them.

[Tanarii]

JNA productions makes a great point: saving throws are reactive to something happening. (Stimulus, response)
Ability checks can be passive or active, but the key point is that they are not necessarily contingent on something else happening. I can decide that I want to pick that lock or try to break down that door, to use two mundane examples, or to grapple that opposing Priest NPC. In play, ability checks are far more flexible than saving throws.
That flexibility, particularly as a tool for the DM, is a plus, not a minus, in play.

Devils argument, shouldn't that mean that:
- noticing a threat is a Wisdom save instead of a Wisdom (Perception) ability check?
- determining that someone is attempting to deceive you is a Wisdom save instead of a Wisdom (Insight) check?

[Thunderous Mojo]

Devils argument, shouldn't that mean that:
- noticing a threat is a Wisdom save instead of a Wisdom (Perception) ability check?
- determining that someone is attempting to deceive you is a Wisdom save instead of a Wisdom (Insight) check?

The 5e system seems to have an unwritten rule that using skills against something tends to result in an opposed ability checks.

Something tries to hide using sneak, something else tries to discover the hidden creature using Perception.

The one exception to this unwritten rule is monster induced grapples.
Many creatures do not have proficiency in Athletics, and most Monsters do have a Strength Saving Throw associated with breaking their grapples.

I’ve often thought that 5e Saving Throws do not add much to the system, and there is not a pressing need to have them in the game.

AD&D Saving Throws we’re clear…if a Saving Throw was called for, taking damage was the least of your worries. Ability Scores had an impact for some types of Saving Throws, but primarily your class was the determining factor for what your target number was.

There also were no Evasion type abilities.

Blade Barrier was guaranteed damage in AD&D. Now Rogues and Monks, (and a few Rangers) can dance through a Blade Barrier with nary a scratch.

Outside of being told that 5e Saving Throws are different then Ability checks, in practice, the two do not feel much different.

[Greywander]

Outside of being told that 5e Saving Throws are different then Ability checks, in practice, the two do not feel much different.

Basically this. It's all 1d20 + ability score mod + proficiency bonus (if proficient). There's no reason ability checks can't be reactive, and often they are (e.g. "As you step across the wooden floor, one of the planks gives way, make an Acrobatics check"). Passive skills also exist, which could allow you to replace a saving throw with an attack roll against a passive skill, similar to what I was suggesting in another thread (where saves become passive defenses, like AC).

TL;DR, saves already function identically to ability checks. They're only different because we've been told they're different.

I'm not necessarily saying that they should be removed, they just don't look much different so the distinction seems little more than semantic. I just feel like they should either be different enough to warrant the distinction, or else they should be combined to streamline the mechanics. Heck, we could even redefine what a saving throw is to simply be a reactive ability check.

[Unoriginal]

TL;DR, saves already function identically to ability checks. They're only different because we've been told they're different

That is incorrect.

On a surface level, both are 1d20 + ability mod + proficiency mod if relevant. But the enormous difference is the last part.

You can get the proficiency mod for an ability check for many reasons. It can be a skill proficiency, it can be a tool proficiency, it can be the DM saying "eh, you have X background, it makes sense you'd have proficiency on this", or anything else. And the skill proficiency doesn't even have to apply on the typical ability check, ex: using Cha mod + proficiency mod because you're proficient in History and you're trying to convince people based on historical arguments, even if you don't have Diplomacy.

The saving throw proficiency, however, can ONLY be obtained by your starting class, by specific (sub)class features which take design spaces that could be used for other features (in other word, if they get a saving throw proficiency they're not getting a different power), or by a feat you can only take once, and the proficiency will ONLY ever apply to the specific saving throw.

You can't go "I'm proficient in DEX save, can't I use my proficiency for this STR save?" the way you can choose either STR with Athletics proficiency or DEX with Acrobatics proficiency to escape a grappling attempt.

If you replace ability checks by saving throws, well, you now have to take into account all the ways the game let you get skill proficiencies or half-skill proficiencies double-skill proficienies. The Bard would be very happy, that's for sure.

So no, the two do not function the same.

[Thunderous Mojo]

So no, the two do not function the same.

At least two of every player character skills are limited to being from a list determined by class.

Skill selections do allow the player more choice then Saving Throws do.
Outside of that, the resolution mechanics used for either is the same.

Indeed, one of the complaints I have seen issued against 5e is the fact that one’s Saving Throws do not all improve over time.

5e in this way is a bit of an anomaly compared to earlier editions.
In the rough and tumble style of AD&D, a single class Fighter became more resistant to magic, and a Magic-User became more resistant to Poison through level advancement.

[Unoriginal]

At least two of every player character skills are limited to being from a list determined by class.

A limited list that is still a bigger choice than which saving throw proficiencies you get. And then you get to choose background skill proficiencies.

Outside of that, the resolution mechanics used for either is the same.

Incorrect.

For example, this:

DM: Alright, make a STR saving throw to resist getting pushed.

Player: Mmmmh, I don't have STR save proficiency, but my character is pretty agile, can I use the DEX save proficiency instead?

DM: Make sense, go for it.

Does not happen.

Getting the proficiency mod to ability checks is purposely easier and more flexible than saving throws. The resolution mechanics are not the same.

[Witty Username]

Take a look at some OSR games. Sharp swords and sinister spells is a pretty straightforward one.
Things it does,
Ability checks, saving throws and attack rolls are the same thing.
There are 4 Ability scores instead of 6, Con and str are 1 score.

Both of which are things you might find interesting.

[Keltest]

Frankly, I suspect the real answer here is that both DMs and players like rolling dice, and having saves becdifferent from checks lets both sides roll the math rocks.

[KorvinStarmast]

Devils argument, shouldn't that mean that:
- noticing a threat is a Wisdom save instead of a Wisdom (Perception) ability check?
- determining that someone is attempting to deceive you is a Wisdom save instead of a Wisdom (Insight) check?

No, it doesn't. Also, Keltest seems to have figured this out.

[Witty Username]

Why are saving throws separate? Class balance. The classes have saving throws much more carefully controlled, only 2 and modulated for class themes and power dynamics (sorcerer getting proficiency in Con Saves, but not Paladin's is the prime example of power concern affected decisions).
Also, skills and saves being separate allows them to be balanced differently. Combining them into one effectively gives the rogue the best saving throws.
And than edge cases like exhaustion not becoming a true death spiral until level 3.

[Sception]

people keep saying bonuses to saves are more tightly restricted than those to ability checks, but that's really only the case for /skill/ checks. bards can get half proficiency to generic ability checks, but that's about it, while every character has proficiency on a couple saves, can buy proficiency on any they want with feats, and there are a lot of bonuses out there for saving throws.

Something that just tells you to roll a straight stat check - not save, not skill - is often much harder to overcome.

For example, Wrathful Smite forces the target to make a wisdom save, and if they fail they are frightened. But to get rid of the frighten they have to give up an action AND pass a wisdom Check - not Save - which is almost always so much harder to do that it's not even worth attempting. There's no equivalent to legendary saves or spell resistance for monster stat checks. no proficiency or expertise to generic strength or dex or con checks that don't have a particular skill attached to them.


honestly, I think generic stat checks probably shouldn't be a thing. A stat check should always be some kind of stat check - attack roll or saving throw or skill check or initiative roll, but something explicit, not just the stat.

[Thunderous Mojo]

Getting the proficiency mod to ability checks is purposely easier and more flexible than saving throws. The resolution mechanics are not the same.

This presumes quite a bit on your part.

A quick example: as a DM, I have a purple worm slap itself against a cavern ceiling to cause a cave-in. The space is confined, so my reasoning was a Dexterity Save to avoid failing rocks was not practical, there is not enough space to plausibly dodge.

So I called for a Strength saving throw, envisioning that someone using strength or leverage could create a pocket of relative safety within the cave-in.

A player of a Rogue with Evasion, inquired why it was a Strength Saving Throw, instead of a Dexterity check. Now in this particular circumstance, I did not alter the Saving Throw, but if the player had provided a compelling reason for a reconsideration or spent an Inspiration point…I probably would have allowed a change.

The monolithic structural divide you are describing might be more true for your game than for others. Though, admittedly, we are talking about a small degree of variance in opinion here.

[LtPowers]

(e.g. "As you step across the wooden floor, one of the planks gives way, make an Acrobatics check")

I would be surprised to see that in any official adventure vetted by WotC. That should almost always (if not always always) be a Dexterity saving throw. A Dexterity check would be called for if trying to avoid a known hazard, not react to the sudden appearance of one.


Powers &8^]

[Unoriginal]

people keep saying bonuses to saves are more tightly restricted than those to ability checks, but that's really only the case for /skill/ checks. bards can get half proficiency to generic ability checks, but that's about it, while every character has proficiency on a couple saves, can buy proficiency on any they want with feats, and there are a lot of bonuses out there for saving throws.

The whole discussion is about what the impact of using ability checks instead of saving throws would be. Ability checks do not get proficiency unless the character has a relevant skill/tool/thing the DM deems as worthy of granting proficiency.

If you want to use ability checks instead of saving throws but don't allow skill/tool/etc to grant proficiency, then you're saying that no one should have proficiency to resist previously-using-saving-throws effects.

[AdAstra]

I said a little about this when I talked about the two being pretty similar in that other thread, but I should probably elaborate on that and have it here.

Just by having bonuses to saving throws and bonuses to checks be different, it allows you to have different effects for each, which does have meaningful effects in gameplay. Yes, both have limits, both have mechanics that can boost them into the stratosphere, both rely on the same fundamental resolution mechanic, but making the limits and boosts different allows mechanics you couldn't otherwise have without basically replicating the division.

For example, a Paladin's Aura of Protection would be pretty weird if it applied to sneaking, and a Rogue's Expertise/Reliable Talent would be very strange when dodging Fireballs. Now, you could always have those mechanics specify that they only apply to "defensive skills" or "active skills" or whatever, but that's just changing keywords around. You might as well build the distinction into the game at the lowest level so it's immediately obvious what applies to what. The abilities that mention Saving Throws are largely defensive, the abilities that mention ability checks are largely for utility with the occasional active use in combat. Removing the distinction either reduces the design space by making everything affect both, or force you to explain the distinction in the effects themselves when you could just have it in one place.

Also, as far as I'm aware, all examples of "defensive" ability checks in the game, ones forced upon the player rather than actively pursued, take the form of contested checks. That I think is mostly just so that you're not contesting an ability check with a saving throw, which would get confusing fast. So I suppose that's a good way to distinguish. Use ability checks when the player is actively choosing how to approach the problem, or when someone is using an ability check on them and they need to contest (luckily, most of the time the latter does result in the former). Otherwise, probably a saving throw.

[Snails]

...For example, a Paladin's Aura of Protection would be pretty weird if it applied to sneaking, and a Rogue's Expertise/Reliable Talent would be very strange when dodging Fireballs. Now, you could always have those mechanics specify that they only apply to "defensive skills" or "active skills" or whatever, but that's just changing keywords around. You might as well build the distinction into the game at the lowest level so it's immediately obvious what applies to what....

Well explained, AdAstra.

We want the design to stabilize and control Saving Throws, and one of the reasons is to avoid Death Spirals. There are ways of imposing Disadvantage or a penalty on a Save, but that is usually of the "this spell" or "the last/next save" variety. We are more "generous" about imposing Disadvantage (or gaining Advantage) for Ability checks.