D&D 5E Sell/unsell me on Magic Resistance and Legendary Resistance

[FormerlyHemlock]

Interesting. A few questions:

Where did you decide which ability to use for magic resistance? Or is it always Charisma?

You gave the Balor a +12. Can I assume that's Charisma modifier plus proficiency? Are all monsters with magic resistance proficient?

You use the reaction mechanic. Let me discuss this:

Any particular reasons why? Please confirm if the following are intentional consequences of this design choice:
1) by spending its reaction on magic resistance, the monster loses in "stickiness" (since it can't do an opportunity attack in the same round)
2) by having to use its reaction, the monster is helpless against a second spell cast in the same round as the first
3) normally you'd reserve actions you take through your reaction to be reactive actions. What I mean is; it seems as if your idea is that the monster should spend its reaction even on its own turn in the "burst the force cage" example.

Next; you did not chose any lethal effects in your examples. Any particular reason why? Do you intend the monster to be able to recover from all spells or only those who impair the monster somehow but without killing it outright?

For example: you bring up Wall of Force. Fine. So Hold Monster and Flesh to Stone presumably works the same way. The monster can be considered still active - "alive but chained". But how about effects that move the monster to another plane? Changes it into a stupid frog? Or kills it outright? Put simply, are you envisioning any limits on what your magic resistance can save you from?

By direct analogy with Counterspell, I'm using whatever ability score corresponds most closely to its relationship with magic. I'd give a Balor Charisma (Magic Resistance): +12 (Charisma mod plus proficiency), and a lich Intelligence (Magic Resistance): +12, etc. For spellcasting monsters you can just read it right off the spell DC.

Just as some monsters have Expertise on skills (goblins have Stealth Expertise and Stone Giants have Athletics Expertise) it could be okay to give some monsters Magic Resistance Expertise. This seems thematic for illithids: instead of Intelligence (Magic Resistance): +7 I'd give them +10 because they're always been highly magic-resistant in lore (90% MR in AD&D!).

RE: your reaction questions, yes, #1, #2, and #3 are all deliberate. Additionally, forcing it to expend its reaction makes it an in-character choice (non-dissociated mechanic) which is cooler to me, and prevents the monster from stacking Counterspell and Magic Resistance (since they're both reactions) or Shield and Magic Resistance. That gives the PCs more ways to get around Magic Resistance if they're clever, e.g. by baiting the monster into making an opportunity attack and then hitting it with a spell.

It was not deliberate or significant that I didn't choose any lethal spells. You could use Magic Resistance to negate four blasts from the same Eldritch Blast spell if you wanted, or a Lightning Bolt, or maybe even (DM's judgment) a Divine Smite. This gives weapons an advantage over spells/cantrips because you don't lose the first successful attack. This is similar to how monks are hard to kill with ranged weapons because of their missile catching reaction--but again, there's an anti-synergy there for monsters because they can't both Shield and Magic Resist in the same turn.

I'm not envisioning any particular limits on what MR can save you from. Hold Monster/Flesh to Stone/Plane Shift/Polymorph/Power Word Kill are all the same: the monster can choose to resist the magical energy and be unaffected by the spell. One particularly nasty (and deliberate) consequence: if you try to use summoned monsters against a Magic Resistant creature, it can disrupt your summoning spell when the summoned monsters hit it. (Remember, if it's an elemental, that means the elemental doesn't disappear--it becomes free-willed and hostile to the caster.)

A lone wizard against a high-MR monster might have to fall back on indirect attacks such as using a Wall of Force as a bridge and then ceasing concentration when the monster walks over the bridge.

As a DM, I would also say that MR doesn't help against most illusion magic, because the magical energy isn't affecting the creature, it's just creating light waves/sound waves/etc. Illusions like Phantasmal Force would be an exception because they do exert a direct influence on the creature, and so could be resisted by Magic Resistance.

 

[FormerlyHemlock]

No, I intended it to work with wall of force. What prevents it from being used with wall of force? What can be revised to added that concept back in?

Also, what is the preference for ability checks versus saving throws? I like that saving throws can have proficiency added and it is in the stat block - makes it easy to determine the DC.

Your version says the creature gets to ignore the effect, but it doesn't have any language about ending the effect. The Wall of Force is still there after the Magic Resistant creature walks through it, in your version, because there's nothing that says it ends. How would a DM know that the spell is supposed to end when it's resisted?

I prefer ability checks because the Magic Resistance I've written is deliberately based on Counterspell/Dispel Magic. There's nothing going on that couldn't be basically accomplished by a well-chosen Counterspell, which means that all the normal counter-countermeasures that players would deploy against Counterspell still work, such as Hex/Cutting Words/fear/etc. Also it makes the fiction very clear: the monster is exerting its will and knowledge of magic to cancel a magical effect. If you're worried about trying to compute the DC for Magic Resistance--for many creatures with Magic Resistance, they'll be spellcasters already so you can just reuse the spellcasting bonus. For others, like dragons, computing the DC requires a little bit of math but it's the same math you'd have to do anyway to add spellcasting to the stat block. I don't see any real advantages to abandoning the Counterspell-based design and switching to saving throws.

 

[dave2008]

RE: your reaction questions, yes, #1, #2, and #3 are all deliberate. Additionally, forcing it to expend its reaction makes it an in-character choice (non-dissociated mechanic) which is cooler to me, and prevents the monster from stacking Counterspell and Magic Resistance (since they're both reactions) or Shield and Magic Resistance. That gives the PCs more ways to get around Magic Resistance if they're clever, e.g. by baiting the monster into making an opportunity attack and then hitting it with a spell.
.

You could allow it to use a bonus action (own turn) or reaction (off turn) or possibly legendary action (extra turn?) This could be a way to increase or decrease its effectiveness depending on the monster.

I like the idea of using expertise as an option as well.

 

[FormerlyHemlock]

That only works if you already have rules for Magic Resistance; if it was a "skill". I was not assuming, this. I just want something simple I can drop into a stat block

If 5E has taught us anything, it is that defining complex abilities with one sentence and no examples is a recipe for DM controversy and player uncertainty. I wanted to avoid that by writing this rule in the style the 5E PHB should have been written in.

 

[dave2008]

Your version says the creature gets to ignore the effect, but it doesn't have any language about ending the effect. The Wall of Force is still there after the Magic Resistant creature walks through it, in your version, because there's nothing that says it ends. How would a DM know that the spell is supposed to end when it's resisted?

Yes, that was intended. I wasn't ending the spell - the monster just walks through it. It ends the spell by beating the snot out of the wizard!

Though I see the allure of it breaking the spell as well. Maybe:

16) Magic Resistance. The dragon can use its reaction to attempt to nullify a spell or magical effect. If the dragon makes a Charisma saving throw (DC = spell level + 10) it suffers no damage, condition, or effect and the spell or magical effect ends.

 

[dave2008]

I prefer ability checks because the Magic Resistance I've written is deliberately based on Counterspell/Dispel Magic. There's nothing going on that couldn't be basically accomplished by a well-chosen Counterspell, which means that all the normal counter-countermeasures that players would deploy against Counterspell still work, such as Hex/Cutting Words/fear/etc. Also it makes the fiction very clear: the monster is exerting its will and knowledge of magic to cancel a magical effect. If you're worried about trying to compute the DC for Magic Resistance--for many creatures with Magic Resistance, they'll be spellcasters already so you can just reuse the spellcasting bonus. For others, like dragons, computing the DC requires a little bit of math but it's the same math you'd have to do anyway to add spellcasting to the stat block. I don't see any real advantages to abandoning the Counterspell-based design and switching to saving throws.

Hmm, I'm not really seeing the difference whether you call it an ability check or a saving throw. However, my rule knowledge is not as great as yours so I will take your word for it.

 

[dave2008]

If 5E has taught us anything, it is that defining complex abilities with one sentence and no examples is a recipe for DM controversy and player uncertainty. I wanted to avoid that by writing this rule in the style the 5E PHB should have been written in.

I can understand that; however, I sometimes like to leave things ambiguous so they can be resolved as needed by the DM.

 

[FormerlyHemlock]

Yes, that was intended. I wasn't ending the spell - the monster just walks through it. It ends the spell by beating the snot out of the wizard!

Though I see the allure of it breaking the spell as well. Maybe:

16) Magic Resistance. The dragon can use its reaction to attempt to nullify a spell or magical effect. If the dragon makes a Charisma saving throw (DC = spell level + 10) it suffers no damage, condition, or effect and the spell or magical effect ends.

I understand where you're coming from--if you think it's cooler for Wall of Force to be ignored instead of disrupted, my twenty-years-younger self would have very much agreed with you. That's how I houseruled MR in AD&D. I think the important point is for it to be clear to your reader how you intend the thing to work, and since your intent matches your verbiage, it sounds like your version is perfect for you!

Similarly, if you prefer saving throws to ability checks, and don't care about things like players being able to impose disadvantage on ability checks via Hex or Fear, then go for it! I think the version you've written would work just fine at your table, and probably be more fun for you and your players than vanilla Legendary Resistance.

 

[dave2008]

I understand where you're coming from--if you think it's cooler for Wall of Force to be ignored instead of disrupted, my twenty-years-younger self would have very much agreed with you. That's how I houseruled MR in AD&D. I think the important point is for it to be clear to your reader how you intend the thing to work, and since your intent matches your verbiage, it sounds like your version is perfect for you!

Similarly, if you prefer saving throws to ability checks, and don't care about things like players being able to impose disadvantage on ability checks via Hex or Fear, then go for it! I think the version you've written would work just fine at your table, and probably be more fun for you and your players than vanilla Legendary Resistance.

I'm not working on this for my table at this point, and didn't give any thought to what was cooler. Just trying to distill what you wrote and explore different options - that is why this was option 16! I like the stat block approach so you have the flexibility to give different types of magic resistance to different monsters. There is not one set general "magic resistance," but a multitude of specific rules. Really is more complex in a way.

Furthermore, I've listed the 16 options so people can pick and choose what they like.

I appreciate the feedback though.

 

[FormerlyHemlock]

I'm not working on this for my table at this point, and didn't give any thought to what was cooler. Just trying to distill what you wrote and explore different options - that is why this was option 16! I like the stat block approach so you have the flexibility to give different types of magic resistance to different monsters. There is not one set general "magic resistance," but a multitude of specific rules. Really is more complex in a way.

Furthermore, I've listed the 16 options so people can pick and choose what they like.

I appreciate the feedback though.

Okay. For the record then, I don't think what I wrote can be usefully distilled (much) past what I already wrote--I already trimmed it down to the point where everything written down is intentional.