D&D 5E The Math of Cantrips with Saves

[Warpiglet]

Hello Smart Gamers

Just had a thought about developing a cantrip warrior and started the discussion in another thread. This question goes more to odds. While I do not mind being underpowered I do not want to be totally gimped.

So a question about cantrips with saves:

I was looking at making a tome pact warlock with touch spells as well as poison spray and acid splash. Often, at range, Eldritch Blast is the bees knees. Up close, not so much. I have a blade pact warlock that I enjoy. However, I was thinking about another path.

Many creatures have a bonus to poison or even dex. Some do not.

How much harder would it be "to hit" the average monster with a save vs. cantrip if bane was active? This would be acquired through one level of bard due to roleplay reasons.

So if we have bane going, how hard would either poison spray or acid splash be to hit with vs. standard weapon and shillelagh or something else.

I know it is a handicap to use cantrips so frequently, but I want to explore a touch attacking, poison and acid producing creep. I would wear armor and have warcaster at level 4...

I can read through the MM sure, but wondered if someone had a rubric that they had developed.

 

[Satyrn]

I know it is a handicap to use cantrips so frequently, but I want to explore a touch attacking, poison and acid producing creep. I would wear armor and have warcaster at level 4....

There's a decent chance when I hit 6th level I'm gonna give my gnome battlemaster Magic Initiate for acid splash and poison spray, flavoring the cantrips as alchemy.

If I had done so at 4th level I could've given you some real, in the field observational feedback.

 

[TwoSix]

Bane adds 0.125*(average cantrip damage) to your expected damage per round. Better than elemental adept; worse than Draconic Sorcerer's bonus or potent cantrip from Evocation Wizard.

Bane isn't bad, per se, but it's objectively worse than its counterpart Bless outside of some fairly uncommon party configurations. Bless hits its targets 100% of the time, Bane is optimistically 60-70% outside of the teen levels. It's rare for a party to do the bulk of its damage with save-causing effects, if they do, it's usually with AoE spells against larger groups, which makes Bane less useful unless it's scaled up. In contrast, the most dangerous effects from monsters tend to be ones that causing throws over targeting AC, this makes the defensive benefits of Bless (+saves) more useful than the defensive benefits of Bane (-attacks).

So generally, Bane is best against groups of brutes (high attack power, low saves and save inducing abilities) when used by a group of primarily spellcasters. Most other configurations favor bless over bane. If your at-will offense is geared around landing a low-impact spell that often fails and, if it lands, eats up your concentration slot, there are probably stronger ways to optimize your concept. Honestly, a character based around cantrip use is really awesome, but is begging for some house rules or homebrew to fully support it.

 

[Warpiglet]

Bane adds 0.125*(average cantrip damage) to your expected damage per round. Better than elemental adept; worse than Draconic Sorcerer's bonus or potent cantrip from Evocation Wizard.

Bane isn't bad, per se, but it's objectively worse than its counterpart Bless outside of some fairly uncommon party configurations. Bless hits its targets 100% of the time, Bane is optimistically 60-70% outside of the teen levels. It's rare for a party to do the bulk of its damage with save-causing effects, if they do, it's usually with AoE spells against larger groups, which makes Bane less useful unless it's scaled up. In contrast, the most dangerous effects from monsters tend to be ones that causing throws over targeting AC, this makes the defensive benefits of Bless (+saves) more useful than the defensive benefits of Bane (-attacks).

So generally, Bane is best against groups of brutes (high attack power, low saves and save inducing abilities) when used by a group of primarily spellcasters. Most other configurations favor bless over bane. If your at-will offense is geared around landing a low-impact spell that often fails and, if it lands, eats up your concentration slot, there are probably stronger ways to optimize your concept. Honestly, a character based around cantrip use is really awesome, but is begging for some house rules or homebrew to fully support it.

that is a good analysis--thanks!

I would be taking one level of bard, so bane is the one. Bless rock, I realize. However, bane would also fit with the concept better as well.

I would be looking to do eldritch blast at range and then was exploring cantrips close up. I am questioning how viable this is....

 

[Barolo]

I would say it should not be a problem in general, if you are able to access your enemies weaknesses and play accordingly. Surely a lot of monsters/NPCs have good con saves, and poison resistance is really common, which would usually imply that the use of poison spray usually requires a little bit more consideration.

At higher levels it may start to hurt more to be dependable on save options, as monsters with spell resistance start to show up, and proficiency in saves for monsters become more commonplace.

All that said, it is wise for a spellcaster to have some save spell as backup even for a more traditional attack-reliant build, if you can afford it, as there are monsters with outstanding AC for their challenge (such as hobgoblins), and you will always eventually find some odd opposition who happens to have as their Achilles heel a con save, even latter on in the game.

Edit: I failed to mention you actually should not be gearing yourself to cantrip-intensive tactics in expense of your other spells in general as a spellcaster. They are, after all, your backup option. The only cantrip truly reliable for intensive use is eldritch blast, for some unique features it has (such as force type damage) and some investments that can be done towards this specific goal, which are only available for this cantrip (or, in the case of hex, best benefited through it).

 

[thethain]

This is going to vary a bit based on lots of numbers.

But assuming you have a +3 ability mod, an attack roll at level 1 would be +5, while your save would be 13. The AC of creatures at CR <3 is going to be around 13 (on average) so that means you have to roll a 8+ (so a 65% chance to hit). Acid splash is a dex save, while poison spray is a con save. Assuming they have a 10 score in the one you target, they have to roll a 13+ to avoid the damage (so a 65% chance to hit).

However, those are all using super standardized values. Some creatures have crazy dex and con, some have really high AC and no dex. The advantage of spellcasters is you get to pick by varying your spells to target what you think the target might be vulnerable to.

The animated armor has great AC, but will have very average Dex/Con saves. (And is immune to poison...). The frost Giant might have OK AC,great Con saves but bad dex saves.

Basically just use logic, Does it seem hard to hit because of armor? Does it seem like it could dodge out of the way, does it seem able to shrug off damage. Target whichever defense is lowest.

Don't forget also that some conditions help one type of attack and not others. For example, being blinded grants attacks against you advantage (but doesn't affect saves).

As for damage types: Poison does have lots of resistances out there... Undead, dwarves, elementals, are all pretty common foes which will just be immune or resistant to poison. Acid is much safer, but still isn't as safe as force. No many foes out there resistant to force.

Also worth considering is that Attacks have 3 possibilities, miss, hit and crit, where saves either hit or miss. Attack spells do 1/20th more damage (even more if you can get advantage) than their save counterparts (before static modifiers).

In short -
Eldritch Blast - only weak on high AC or melee (w/o warcaster)
Poison Spray - Good damage, but almost every monster has some con bonus and poison resist is common
Acid Splash - good if they don't have high dex, but needs 2 targets or bad damage.

Shocking grasp is a really nice melee spell to have as it gets advantage if the target has metal armor, and prevents reactions, so you can withdraw after without provoking an attack.

 

[Warpiglet]

This is going to vary a bit based on lots of numbers.

But assuming you have a +3 ability mod, an attack roll at level 1 would be +5, while your save would be 13. The AC of creatures at CR <3 is going to be around 13 (on average) so that means you have to roll a 8+ (so a 65% chance to hit). Acid splash is a dex save, while poison spray is a con save. Assuming they have a 10 score in the one you target, they have to roll a 13+ to avoid the damage (so a 65% chance to hit).

However, those are all using super standardized values. Some creatures have crazy dex and con, some have really high AC and no dex. The advantage of spellcasters is you get to pick by varying your spells to target what you think the target might be vulnerable to.

The animated armor has great AC, but will have very average Dex/Con saves. (And is immune to poison...). The frost Giant might have OK AC,great Con saves but bad dex saves.

Basically just use logic, Does it seem hard to hit because of armor? Does it seem like it could dodge out of the way, does it seem able to shrug off damage. Target whichever defense is lowest.

Don't forget also that some conditions help one type of attack and not others. For example, being blinded grants attacks against you advantage (but doesn't affect saves).

As for damage types: Poison does have lots of resistances out there... Undead, dwarves, elementals, are all pretty common foes which will just be immune or resistant to poison. Acid is much safer, but still isn't as safe as force. No many foes out there resistant to force.

Also worth considering is that Attacks have 3 possibilities, miss, hit and crit, where saves either hit or miss. Attack spells do 1/20th more damage (even more if you can get advantage) than their save counterparts (before static modifiers).

In short -
Eldritch Blast - only weak on high AC or melee (w/o warcaster)
Poison Spray - Good damage, but almost every monster has some con bonus and poison resist is common
Acid Splash - good if they don't have high dex, but needs 2 targets or bad damage.

Shocking grasp is a really nice melee spell to have as it gets advantage if the target has metal armor, and prevents reactions, so you can withdraw after without provoking an attack.

To be anywhere near effective, one would have to actually use strategy. That sounds like fun actually. I really like the idea of sizing up opponents too--if it is lightning fast, probably want to target something other than dex and so forth.

By the same logic, I would want a big toolbox if I really was going to do this few weapons. And I would only want to prep with Bane if using one of the save spells.

Bottom line is melee would be "interesting." I am going to have to think this through but the analysis really helps.

 

[Cognomen's Cassowary]

A copy-and-paste from my musings on save types in my guide to wild-magic sorcerers. Disclaimer: there's a lot of generalizing here, and no accounting for DM tendencies.

I would address something more to your situation, but I'm at work at the moment. (Shh, don't tell.)

A slightly less cursory glance reveals that, if you plot the median of each attribute at each challenge rating, Dex is the only one that trends downward as CRs get higher. This doesn't mean that Dex gets easier to hit as you go up in CR, because proficiency in Dex saves becomes common after a point, but it does mean that Dex gets easier to hit relative to just about every other attribute. Notionally, spells which target Con should be better against crowds of weaker, faster enemies, but there are in fact very few CRs where Dex is not generally the better option.

If you were to take it a few steps further and find the median save proficiency bonus for each attribute at each CR and then weight them against an overall 60% chance to deal full damage (i.e., to hit with an attack, or to cause a failed save) to generalize each attribute's percentage chance across all CRs, you would find these things:

Str starts high, rises steadily, and finishes high. However, proficiency in Str saves is only common at a couple of very high CRs. Str's generalized percentage is 56.28%.
Dex starts high, slowly declines, and finishes low. Proficiency in Dex saves becomes common around CR 10. Generalized 66.54%.
Con starts high, rises steadily, and finishes high. In addition, proficiency in Con saves becomes common around CR 9. Generalized 47.01%.
Int starts low, rises slowly, and finishes low. Proficiency in Int saves is only common at five CRs with 12 being the lowest. Generalized 71.02%.
Wis starts moderate, rises slowly, and finishes low. However, Wis saves are common or semi-common at every CR from 8 upward. Generalized 57.06%.
Cha starts low, rises steadily, and finishes moderate. Cha saves are common at every CR from 9 upward. Generalized 54.47%.
AC starts high, rises slowly, and finishes moderate. However, there is no such thing as proficiency in AC. Generalized 67.62%, which I raise to 72.62% when generalizing a spell's damage, because of the chance to crit.

Taking that all together, considering the entire CR spectrum, the preference for targeting should be AC (72.62%), Int (71.02%), Dex (66.54%), Wis (57.06%), Str (56.28%), Cha (54.47%), and finally Con (47.01%).

To break it down into tighter groupings, moving from best attribute to target to worst . . .
At CRs lower than 1, target AC, Int, Cha, Str, Wis, Con, and Dex.
At CRs 1-4, target AC, Int, Cha, Wis, Dex, Con, and Str.
At CRs 5-8, target Int, AC, Cha, Wis, Dex, Con, and Str.
At CRs 9-12, target AC, Dex, Int, Str, Con, Wis, and Cha.
At CRs 13-16, target Dex, Int, AC, Str, Wis, Cha, and Con.
At CRs 17-20, target AC, Dex, Int, Str, Wis, and then Con and Cha in a tie.
At CRs 21-24, target AC, Int, Dex, Wis, Str, Cha, and Con.
Against a tarrasque, if running away isn't an option, target Dex; Int; Wis and Cha tied; Str and Con tied, and AC sort of tied with them. (The tarrasque is unaffected by all ranged spell attacks and has a chance to reflect them back at the caster, so don't even try. It also has advantage on saving throws against spells, legendary resistance, and resistance to nonmagical weapons, among other things, so there aren't really a lot of ways that fighting it doesn't look like suicide.)