D&D 5E How to defeat creatures with legendary actions?

[tommybahama]

Our DM likes to target spell casters and will ignore high AC martial characters in favor of chasing down spell casters. How do you deal with enemies that can use a legendary action to move after another player without provoking opportunity attacks and can choose to save from a spell?

The next big fight will probably be indoors. The party consists of an AC 20 sword and board paladin, a celestial warlock that likes to fight mid- to front-line (?!?), a barbarian with low HP that always recklessly attacks with GWM, an eldrich knight, a battlesmith artificer, and a circle of shepherd druid. Nobody is min/maxed and several aren't optimized. All are 9th level, but the next big fight will probably occur at 10th. Resources (gold and magic items) are very scarce.

 

[S'mon]

Our DM likes to target spell casters and will ignore high AC martial characters in favor of chasing down spell casters. How do you deal with enemies that can use a legendary action to move after another player without provoking opportunity attacks and can choose to save from a spell?

The next big fight will probably be indoors. The party consists of an AC 20 sword and board paladin, a celestial warlock that likes to fight mid- to front-line (?!?), a barbarian with low HP that always recklessly attacks with GWM, an eldrich knight, a battlesmith artificer, and a circle of shepherd druid. Nobody is min/maxed and several aren't optimized. All are 9th level, but the next big fight will probably occur at 10th. Resources (gold and magic items) are very scarce.

Ranged attacks spells etc that force the target to use up its Legendary Resistances, before you hit it with the big save-or-suck stuff.

 

[Stormonu]

Wall of Force/Wall of Stone for a start, unless the BBEG can move over or through them somehow. Other barrier spells or effects that create areas of difficult terrain might be able to constrain movement. Conversely, if the spellcaster can effect movement of their own (flying, staying behind a literal wall of fighters or the like, staying beyond 60-90 feet and using long range spells), you force the BBEG to waste legendary actions merely to get to the spellcasters or change their attacks to focus on others.

Also, legendary resistances is usually only so many uses. Bombarding the enemy with multiple save-inducing attacks will wear those resistances away or at least force the enemy to consider which to use it against. Attacks that hit using attacks rolls instead of saves may be more effective to use as well.

 

[Nefermandias]

A 5e party is virtually unkillable at this level. I don't blame your DM for ignoring the high AC frontline and going after the casters. That's the least he can do to make fights somewhat of a challenge.

 

[MarkB]

Bear in mind that every legendary action the opponent uses to move is one that he isn't using to make an extra attack or some other direct offensive measure. If all he's doing between players' turns is moving, that's probably less damaging overall.

For legendary resistances, make sure the spellcasters prepare plenty of lower-level save-or-suck spells, and go heavily on them in the first couple of rounds. Then they can open up with the high-level spells once his resistance is worn down.

 

[DemoMonkey]

Have the spellcaster take the ready action to run away from the bad guy if he moves towards them. (If they can get a spell off at the start of the combat that they can continue as a bonus action, or have a bonus action spell to cast, that would be a...bonus).

One player giving up their attacks, in order to waste the Big Bads Legendary action, is a trade-off a party of 6 adventurers will win.

 

[MatthewJHanson]

You're a few levels from the next ASI, but the sentinel feat is designed specifically for high AC martial characters who don't want to be ignored.

You can also look at the making the other targets less attractive. Everybody who can take shield should. Druid can wild shape to get a bunch of extra hit points. I'm not sure why the barbarian has low hp, but if they can change that they should.

 

[Eltab]

An Arrow of BBEG Slaying ought to mess him up, or at least draw his attention. Bonus if the archer can crit.

Yes this happened to me as DM. Arauthator (dragon - Rise of Tiamet) went from max'ed out Ancient Dragon HP to average Adult HP on Round One, and I had to be careful thereafter.
I lost in the end because attrition.

Surely BBEG has an old enemy who won't mind using adventurers as cats-paws to mess with him a little?

 

[jgsugden]

A 5e party is virtually unkillable at this level. I don't blame your DM for ignoring the high AC frontline and going after the casters. That's the least he can do to make fights somewhat of a challenge.

Note that he did say the PCs were not optimized. When PCs are not optimized, or players are still relatively new (first few years) to the game, the suggested level of Deadly encounters can remain a challenge all the way through.

Further, as a DM, when a player says something like this, I like to remind them not to take anything for granted. I promise you that any 9th level 'by the book' party can be TPKed by an encounter that isn't even deadly if the DM really runs the right bad guys cleverly.

 

[tetrasodium]

Our DM likes to target spell casters and will ignore high AC martial characters in favor of chasing down spell casters. How do you deal with enemies that can use a legendary action to move after another player without provoking opportunity attacks and can choose to save from a spell?

The next big fight will probably be indoors. The party consists of an AC 20 sword and board paladin, a celestial warlock that likes to fight mid- to front-line (?!?), a barbarian with low HP that always recklessly attacks with GWM, an eldrich knight, a battlesmith artificer, and a circle of shepherd druid. Nobody is min/maxed and several aren't optimized. All are 9th level, but the next big fight will probably occur at 10th. Resources (gold and magic items) are very scarce.

It sounds like it might be time to have a talk with the GM, unfortunately it won't be an easy one because wotc is still telegraphing the problems of 2e & 3.x. Worst case you can have the casters just nope out "I cast $badcantrip" every round & add "then move here to put more distance" when needed. Top it off with "sorry bob I didn't prepare healing word so I could cast freedom of movement (or whatever) on merlin & used my 4th level slot doing that" it . Wotc is at fault for creating this problem.

In past editions casters had powerful spells that needed to be used with care & thought to avoid running dry & not having them when needed. Martials had other abilities to protect the squishy casters like notable movement based AoOs & such too. In 5e the spells are weaker in almost every way & monsters are often designed to counter the powerful spells of past editions. Unfortunately wotc devotes so much effort to combating the LFQW of past editions that they impress upon GMs that they get the impression they too should combat it even after WotC inverted it badly into LWQF. When someone says "but fireball" or whatever you can show them how screwed the math is

edit: There are good reasons for going after casters sometimes but it sounds like this is well beyond that