How can I make a single level 20 Warlock/Paladin a climactic challenge for a party of 4 level 12 PCs?

Question

So, I know this question seems silly on face because of the level disparity (and I'd even be willing to adjust the character level down if necessary) but what I'm most concerned about are action economy and save-or-suck effects.

For a little background:

The Paladin is the former spouse of one of the party members, alignment swapped by the Balance card from the Deck of Many Things. The party wants to face her, take her alive, and switch her alignment back by forcing her to wear a magic nose ring of Reverse Alignment.

This is supposed to be a huge culmination of many sessions of planning and intrigue, and I want to pay it off right. There will be a lot of negotiating and roleplaying, which I'm confident about running, but once they reach an impasse combat will almost certainly happen, and that's where my worries start.

What I don't want to happen:

1. Paladin loses initiative, all four party members get to attack, reducing her to less than half of her 158 hit points. She has to use her turn either healing herself or running away, or else die the following round.
2. Paladin doesn't lose initiative, maybe does heavy damage or even incapacitates one PC, but then either the Cleric or the Wizard casts a fight-ending spell like "Hold Monster", "Polymorph," or "Dominate Person." The Paladin's Wis save is +9, but the Cleric's save DC is 19 and the Wizard's is 17, so there's still roughly a 50-50 chance of this working. They slap the nose ring on her and the danger is over. Even a spell like "Command" would be devastating in this context.

Solutions I've Considered:

1. Add more NPCs to the encounter to balance the action economy. This is pretty straightforward, but I'm still worried about save-or-suck effects that take the Paladin out of the fight and end the conflict. I'm also worried that adding more NPCs will take the encounter balance too far in the other direction, downing the party before they have a chance to do anything. Plus, I don't want to add so many other NPCs that the intimacy of the encounter is lost.
2. Give the Paladin Legendary Resistance, or some magic item that allows her to resist spells, such as an ioun stone or rod of absorption. This solves the save-or-suck problem, but in a way that feels like it directly invalidates the casters' powers. Also, since I'm building the Paladin as a PC, Legendary Resistance feels cheap, and I'm not super excited about giving my players access to a Rod of Absorption after the fight.

Even though I'm not thrilled with these options, I could throw them together and call it a day. What I'm looking for are times when you've run/participated in similar scenarios, and what you/your DM did to try and balance them.

Answer 1

Learn to embrace fortitious outcomes

I think fundamentally, while you can use tricks to mimic legendary resistance and legendary actions and more hp, you don't need to have a fight that drags out over multiple rounds for the encounter to be memorable.

You are afraid that the PCs, after lots of planning and preparation win intiative, get off a lucky hold person, and put the nose ring of alignment reversal on the paladin to win her back? Why? The party will love it when a plan comes together like this unexpectedly. Encounters where the BBEG gets downed with a single lucky spell can be extremely memorable and become part of the groups fond stories. Add embracing them to your DM arsenal. In the end, forcing a multi-round, dragged out fight to get to the same conclusion (or to have the paladin evade, invalidating all the effort and frustrating the players) is just soft railroading how the fight will play out, because you think that is going to be more awesome. But it isn't, and you don't need it.

You also do not need to worry that the party will kill the paladin -- they can easily deal non-lethal damage to knock her out, and then put on the ring while she is unconscious.

Working to ensure a multi-round fight

If you insist on a multi-round fight, from my experience with running single foe combat against a full party at high levels, I have the following learnings:

1. You need legendary resistance, legendary actions. There is a reason these legendary features exist, to make such fights feasible, otherwise the action economy or disabling spells will end the fight early. You can try the lucky feat, or a potion of speed, to mimic legendary resistance and legendary actions to some extend.

2. You need a large pool of hit points or strong healing features that do not cost actions to use. Healing yourself in mid-combat is not a viable strategy: first it consumes your action most of the time, and second there are no healing spells that a paladin has access to that can keep up with the damage, so its a losing race. A party of four 12th level characters deals over 100 points of expected damage if they are even decently built, maybe a bit less if the paladin has unusually high AC. Even heal, that a paladin has no access to only heals 70 points, and potions of superior healing just heal 28 points. PCs are relatively low in hp compared to typical paragon-tier monsters who have several hundreds. You can do a little with a pre-upcast aid spell, but it's not going to make a huge dent. She also could have eaten a heroes' feast the last night, which would add another 2d10 temp hp, and also help with "legendary" saves by granting advantage to Wisdom saving throws. Good intiative is probably the biggest tool here, by giving the paladin one round of actions more before hp run out, so you are looking at a two-round fight instead of a one round fight. You can take the Alert feat. If you already took Fey Touched as a feat, and you allow it, you can pick Wildemount's gift of alacrity as the selected spell that adds 1d8 to initiative for 8 hours, saving you a feat (or furhter boosting it to an expected +9.5 mod). As magic item options, a sentinel shield or weapon of warning can give you advantage on the roll. (And of course, Lucky can do double duty, here too).

3. You also should think about the ability to fly at good movement speed or solid ranged combat capabilites unless you want the PCs to take flight and finish of your monster with ranged attacks at no risk. Paladins are normally melee combatants, so a potion of flying, or maybe winged boots, if you don't mind her to have them afterwards.

4. if the monster is not huge, it needs a way to get out of a forcecage which has no save against being put into (available to level spell level 7 casters such as your party), for example by being able to teleport (with misty step or similar), having disintegrate, etc. The Fey Touched feat can provide you with misty step and also can boost Wisdom or Charisma, which is useful to a Paladin.

Still, instead of pushing this to be a multi-round slough with consumables, temp hp, initiative boosters: consider the encounter as a well executed reunion fight.

Answer 2

Single boss monsters have quite a few issues that I don't think you'll be able to guarantee things work out how you'd like with the PC rules, but you can make it quite likely things work out in your favour.

Initiative

• Feat: Alert - +5 initiative goes a long way to going first
• Feat: Lucky - this will be your main tool for probability manipulation, it's discount legendary resistance for PCs, and you can also use it on initiative and against martial characters attack rolls if needed
• Optional magic item: Sentinel shield - an extra chance to roll for initiative goes a long way

Preventing Save or Suck

No matter how you do this it will feel bad for the spell caster, but at hopefully the fact that they are burning through the enemy's resources will make it palatable.

• Feat: Lucky - As mentioned, this will be a weaker version of legendary resistance, you can reroll if a bad spell lands
• Fiend Warlock level 6: Dark One’s Own Luck - An extra D10 to add to a save if needed
• 4th Level Spell: Find Greater Steed (Paladin level 12) + Spellwrought Tattoo: Dispel Magic - The steed adds a fairly weak companion to the encounter, but one that should be strong enough to not die instantly and that is purely a part of the paladin's capabilities. You might not want to allow this but it should be within the rules to allow the steed to attune to a magical tatto of dispel magic allowing it to cleanse an otherwise encounter ending spell once. (You could also use a squire with a spell scroll for this.)

In my own experience

Legendary actions and resistances are vital to running a single boss monster encounter, I don't really recommend running one without them but the Lucky feat will sort of work. What I've done in the past to avoid legendary resistances feeling like a spellcaster specific nerf is have an encounter where the main objective was to break the near unkillable BBEGs concentration, so burning through them was necessary for the whole party whether by save or suck spells or high damage to force a concentration save failure.

Answer 3

The suggestions given in the other answers are very good.

I would add that you could use the location of the fight to help the boss. Perhaps the paladin is attuned to the area due to a magic aura aligned with their deity or cause. This could provide healing and magic teleportation for them during this fight, but sidestep giving it permanently, or worse, as an item that the PCs get to use later.

Also, traps and lair actions are good for this. You could add minions or support monsters, but these take time to kill. But a trap usually goes off once or a few times, and is done, or at worst, the PCs have to disable it with an action or two.

Good luck creating a memorable moment, but don't force it. I've found that memorable moments seem to come on their own.

Answer 4

Add flavour text to legendary resistance style abilities.

If the paladin is restrained by a spell, they explode with dark energy and everyone now has to save vs necrotic damage. They rise out of a flaming crater and they have wings made of crow feathers now. They deliver a short monologue about how the PCs efforts are futile.

They just used a legendary resistance but it won't feel that way, because there was a scene change. Now the paladin is flying and letting loose eldritch blasts. Can a paladin or a warlock develop wings and fly? Well, actually, kind of yes. Several abilities of those classes let you fly. Likewise both classes can deliver large aoe attacks. All you're changing is letting several of these things happen as a Reaction instead of each taking several actions, and bundling them together as a reaction to failing a save (ideally letting a couple of PCs do things between so they can get a hit in while the paladin is Hold Person'd or whatever).

This kind of 'multi-stage boss battle' is well understood by players, from videogames and also makes intuitive sense - someone pulling out a trump card when you have them on the ropes is just logical. If they can't use it many times or it costs them something, it's best kept until necessary.

Alter the paladin's tactics when this happens. They now fly around using Eldritch Blasts. If they take enough damage or fail a save again, change the stage again. Perhaps they are now trying to escape and it's a chase scene where the PCs' move speeds and ability to teleport, climb, swim or even ride mounts will be tested in a chase scene vs a fallen paladin who summons their version of find greater steed - a fire-hoofed Nightmare.

Essentially, turn a boss battle into several almost-separate encounters that require different tactics to defeat and allow PCs to use their abilities and/or improvisation or plans to defeat the enemy several times. That will make the ultimate victory far sweeter.

Likewise, this paladin should be tough. Level 20 vs level 12 is not a huge difference in 5e, except in terms of alphastrike spells (which the paladin doesn't have) or alphastrike melee bursts (which the paladin does have technically but using that on PCs is lame). 5e has tough but low damage monsters and squishy but high damage PCs - pvp often becomes rocket tag. On top of that, level 20 warlock/paladin has little synergy in a single battle. Warlock/Paladin is a short rest, many fights combination at best. A level 12 paladin may be stronger than a level 10 warlock/level 10 paladin.

Offer infernal boons. Local warlock patron may not want their servant getting bazonked by a team of four goody two shoes. These boons may have a cost. Maybe it is visibly burning their body out, helping them but at some terrible cost, giving the PCs reason to try to bring things to a close as fast as possible (and thus take risks). Either grant the paladin two actions per round (what 5e calls 'lair actions') or their actions need to be about twice as powerful - 4 melee attacks or 8 eldritch blasts per turn. Otherwise a single Life cleric can literally heal through their turn. Assuming they aren't being optimized - a Great Weapon Mastery Polearm Master Smiteadin can do enough damage to threaten a team without needing additional actions. But if they're a sword and board generic heroic paladin type they will need help.

Likewise, they shouldn't have a 50/50 shot at losing to a single spell from one of their four opponents. They should have boosted saves that push the chances much higher, so casters might hit that lucky save or lose or they.. might not. Keep in mind, any failed save can end the fight at this level. Even with the 'scene change' legendary resistances, you could have the scene change over 3 consecutive player turns as you fail vs hold person, dominate person, and then get crit by a fighter with action surge and unleash incarnation to the point that the paladin doesn't even get a combat turn. You will want to beef up these stats if you want the paladin to be an actual combat encounter that the party could lose (even by the paladin escaping). You want roughly a 80% chance of saving vs spell effects, especially as the paladin is a Humanoid type and not a Monstrosity or w/e (although you could make one of their forms a Monstrosity (or Fiend/Abberration/whatever) if you wanted, as they get twisted by the infernal power of their dark master(s)).

Likewise you want 5-6 player turns of hp damage based attacks of hp between 'forms'.

If the warlock levels have access to powerful aoe spells like fireball or cloudkill or what have you, this changes the math. PCs are weak to aoe attacks and it changes combats considerably if they are in the mix. It's why they are relatively rare on monsters and don't typically hit super hard. I'd avoid giving the paladin/warlock such attacks except as very rare things, like one at the start, or during one of the scene changes.

Answer 5

NPC's don't have levels. Npc's and monsters have a profile that is similar to that of PCs, but it isn't the same and it's arrived at differently.

D&D 5e is not built to expect something built like a PC to play well as an adversary in a combat encounter. What you want is something of an appropriate CR for the challenge you want the party to face. One CR 12 monster is a medium encounter for a party of 4 12th level characters, so for a hard encounter you can either add some minions, or go up to CR 14.

We can take inspiration from the Archmage in the MM, as that is a CR 12 foe that has spells that reach 9th level and 18 HD.

When I think of high-level Paladin, I think of someone riding a flying mount, which also means that you don't have to push all the challenge onto just the NPC. You still might want to give them legendary resistance and some legendary actions, because there's still a big disparity in the action economy.

Answer 6

Are you considering custom magic items?

Things like an amulet with a few charges of Counterspell could buy a little time for the Paladin to stretch out the fight, without feeling too cheap or giving the party access to an unbalanced toy afterward. For extra drama you can describe one of the big gemstones on the amulet glowing and then burning out as the spell fizzles.