Having difficulty making a spellcaster villain fairly balanced against the party

[tchntm43]

We have a party of 4 Level 4 characters (dwarven fighter, human bard, human wizard, and tiefling ranger). In designing the next adventure, the primary villain (a human Evoker) would be encountered either alone or with very low-level minions (probably Guards from the MM, they're like 25 XP each). So since it's basically 4 on 1, I figure the villain can be stronger than individual party members. But even bumping her up 1 level above them gives her access to level 3 spells, with 2 slots at that level, and it would be hard to justify her not having Fireball and Lightning Bolt given her class. Both of these spells do 8d6, and it seems like Fireball in particular could TPK the entire party potentially. The dwarf has enough hit points to survive one failed save, and the Tiefling will only take half damage, but with 2 slots she can potentially cast it twice, and as an Evoker she can use sculpt spells to not be hit by her own fireball. I was thinking I could set up the encounter to be geographically unfavorable to casting those spells (meaning that she might still cast them but neither would hit everyone), but this is in her stronghold, and why would she build it in a way that make it unfavorable to cast her best spells? It's also my intent that the party interacts with her several times before they discover what she's up to, so combat is not the first thing that happens unless they make a bad decision.

It seems like the jump in power from level 4 to level 5 for wizards is pretty huge, due to the difference in power between level 2 spells and level 3 spells. I feel like if I give this villain only level 2 spells, then they don't present a challenge at all. I'm open to an alternative but I'd like a solid evil spellcaster that is powerful enough to give the party a fight (and definitely too strong for them to go one-on-one with), but also isn't going to easily wipe the party out and have the players angry with me. I've checked the pre-made NPCs in the back of the MM and Volo, and they all either seem too strong (almost all the wizard types) or too puny (the apprentice mage).

[1Pirate]

Give her only one third level slot(have the other one already expended for some reason. Bonus points if it's because of something clever the party did earlier, like they tried to create a diversion in some other room and she used a fireball without checking).

Make sure the party knows what she's capable of so they can try to strategize around it getting fireballed(again bonus points if they can do something creative to get her to waste the slot somehow).

[Bobthewizard]

Spellcaster NPCs are tough to balance. If the players win initiative, the fight will be over before the Evoker gets to cast a spell. You could consider making a level 3 wizard with minions act as the BBEG so the party uses their NOVA abilities. Then have them find the real BBEG with some more minions. 5th level Evoker seems fine for a final fight. I like the idea of having the players witness him cast a fireball on others first. Then throw one at them to take some characters out. If they spread out, he won't take them all out. He should be easy for the remaining characters to kill. Adjust HP appropriately.

There is disagreement on whether evokers can exclude themselves with sculpt spells. "When you cast an evocation spell that affects other creatures that you can see, you can choose a number of them equal to 1 + the spell's level" could be read to not allow the caster to exclude themselves. So if that ruling helps you, use it. Not trying to start a RAW v RAW battle on your thread since some seem adamant in their interpretation, but it is something you could consider.

[Vorpalchicken]

I have a feeling your group is going steamroller this enemy, 3rd level slots or not. Really, the bard can bring up whoever doesn't make a save and likely only one or two will go down from one fireball. You could also telegraph that they should expect fire damage and suitably prepare. Possibly you could make fire resistance available in limited quantities. Or for a dear price.

I'd probably use the CR 5 transmuter (9th level) stat block (with ability switched to sculpt spell) or even an entirely different creature but described as wizard. Maybe the evoker turns herself into a Fire Elemental or on a Flameskull the first turn of combat!

I don't like using player character builds for opponents to be honest.
But if you do and are worried, you could have the evoker cast defensive spells like with Blink with her 3rd level slot (s) or reserve a few for counterspell.
Or maybe the warning that the players get is the charred remains of the previous targets she just burned her 3rd level slot(s) on.

[tchntm43]

Give her only one third level slot


I like the idea of having the players witness him cast a fireball on others first.


You could also telegraph that they should expect fire damage and suitably prepare. Possibly you could make fire resistance available in limited quantities. Or for a dear price.

This is a great idea I am going to run with. This person manages an arena where slaves are brought in to fight to the death for entertainment. So, when the party sees this happening for the first time, she's gonna get bored and launch a fireball killing both combatants, just because the fight was taking too long.

Thanks a lot for the suggestion! I forgot that it makes sense that spellcasters encountered will often be missing a spell slot or two from previous activities.

[J-H]

You could also have her use other 3rd level spells, like Minute Meteor or Slow.

[firelistener]

I recommend giving the wizard some wards to get through, a legendary action to prevent getting wrecked by bad initiative, and a "second wind" set of HP. By that, I mean have the villain's HP reset the first time they hit zero to prevent them getting one-shot by extreme nova/burst damage. Doing that has helped me keep the fighter and paladin from nuking legendary enemies before they can get attacks off.

[PhoenixPhyre]

As a general note, pure spellcaster NPCs tend to be glass cannons. And glass cannons disintegrate real bad without front-line support.

Take, for example, the Archmage. CR 12, 18th level wizard casting. Adjusted defensive CR: 4.5. Yah. That means a level 4 party should be able to kill one within 3 rounds without an issue. Depending on spell load-out and actions, he runs between offensive CR 10 and offensive CR 20+. Hits like a truck...can't take a hit.

Minions are your friends in this sort of thing. Even weak ones--a bunch of Guard NPCs mean that the party has to split their fire and gives you a lot of cushion for either pushing harder or pulling back. Not having minions means it's all or nothing, decided in the first turn or two. It's likely that a well-built party that wins initiative will nuke any non-guaranteed-TPK (and several of those as well) before the NPC gets a turn.

[Nhorianscum]

3rd level spells are fine. Just run lightning bolt over fireball to remove the chance of tpk.

If anything the caster in question is on the weak end of the spectrum for 4 4th level char's

[vexedart]

If I want to make an intelligent villain difficult, I put them in a favorable position with terrain that favors them.

Give them misty step. Have them animate undead with ranged weapons, teleport when the melee get close so you aren't locked down. Make getting to you difficult terrain via a trap/switch. You're supposed to be smart as clever as a wizard anyways.

Want to be an ********? Put the wizard in a huge locked iron cage. Want to be a bigger ********? Suspend it from the cieling. Have high positions the wizard can cast spells from that are difficult to get to. Use cover to avoid counterspells. Use misty step to teleport to other difficult places.

Just be careful, if the terrain is to far in the enemies favor it can wipe the party.

[Eldariel]

Have him burn one 3rd level spell keeping Animate Dead minions around. Coupled with a familiar, that's a lot of meat to get through. Makes him harder to get to and less able to nuke the PCs. Also use general misdirection magic to somewhat even the odds. Have him start with Mirror Image active. Also judicious use of Minor Illusion, Fog Cloud/Silent Image and company. He doesn't need to see the enemy for AOE nukes. The PCs? Not so lucky. Bat familiar with Blindsense could feed him realtime location data too (still total concealment).

[Bjarkmundur]

4 PCs at 4th Level
Hard Encounter = 1500xp

This makes one 3CR Evoker and four 1/4CR bodyguards seem just perfect. Make the bodyguards have my Tank theme (https://docs.google.com/spreadsheets/d/1d92XLmQN2lmndBbekd6Ns3pDjdLE__FHGGmSWLUVOOM/edit?usp=sharing), which is just a normal stat line modified to give him more to-hit, more HP and more AC at the cost of damage, making it a very effective melee controller. It also gives you more room to beef up the damage of the Evoker by making him contripute most of the damage for this encounter. Give the tank some ability that discourages attacking the mage, something similar to the marking mechanic or that shield fighting style I can never remember what is called. You could also use displacement such as shove, or stickyness such as Sentinel feat and grapples. The tank works with a catch-22 tactic; their AC is so high it's kinda silly to attack them, but meanwhile they are doing everything they can to grap your attention. It's suboptimal to get grappled, but its also suboptimal to try to hit an AC of 16 when there's a reeeaaalllly angry wizard blasting your party down.

It is recommended to have two mini bosses rather than a single boss, just in case one gets hit by something like hold person + divine smite. You should have some backup-challenge in case the evoker bites the dust too soon for the encounter to meet its required drama level. Something simple is best. Maybe there's some other mega-bodyguard (like The Mountain from GoT), or maybe the mage just uses his final breath to cast a Bead of Fireball (https://roll20.net/compendium/dnd5e/Necklace%20of%20Fireballs#content), or falls flat on his face as he dies, triggering a single bead under his corpse, damaging anyone standing too close (and of course, repaints the room crimson).

1/4CR Bodyguard
AC: 16
HP: 15
Attack :6
Damage on hit: 3
DC: 10
Save: +2

3CR Evoker
AC: 14
HP: 60
Attack: 6
AoE Normal Attack: 10 damage
AoE Special Attack: 20 damage
Single Target damage on hit for each round: 20 damage
DC: 13
Save: +5

The CR-to-PC Level ratio is about 1:3, meaning that a CR 3 evoker is a 1st level 'PC'. You can of course reduce his HP by half in order to get increase his spellcasting capabilities without having to increase his CR, like is done with the Priest (https://www.5thsrd.org/gamemaster_rules/monsters/priest/). I for one recommend me aforementioned Necklace of Fireballs (https://roll20.net/compendium/dnd5e/Necklace%20of%20Fireballs#content), which the PCs can then gain as a reward (maybe just with two beads remaining). If you decide to give him a way of casting higher levels spells, even with the necklace, without lowering his other statistics to compensate, the damage and save DC should be moderated to match the difficulty level of the encounter. So a fireball would deal no more than 20 damage per failed save DC 13 save if you used the statistics I provided even though the fireball's damage is usually 28 damage save of 15 or higher. 20 damage DC 13 is the average limited-use AoE ability for a CR3 creature.

You could have the Evoker use the Archer theme, which sacrifices a lot of AC and HP in order to get higher Damage. This is not recommended for bosses, but might work to fit your encounter:

AC: 11
HP: 30
Attack: 8
Damage Budget: 30
DC: 13
Save: +5

Workshopping monsters is a lot about knowing what difficulty level your players can handle without a TPKO, and then managing the resources a monster has in order to match that difficulty level. A monster with only 1 HP for example could deal easily deal 30 damage AoE auto-hit, and be a good challenge for a level 4 party. Some party members will go down, but at least one will probably survive the hit, kill the monster and stabilize his allies. That doesn't make a very engaging encounter though, so you probably move some of his power from the damage to the HP. Then move some of the power from his hit percentage to having minions etc etc.

If you want to let an enemy do something that is usually over that enemies power level, without changing the stats or CR, have it be an item the players can get as a reward. This 1st level caster might have some 3rd level spell scrolls in his bag. This allows him to cast 3rd level spells, but it also increases the reward for the players since they get some scrolls as loot! This also adds to the consistency and verisimilitude of your world.

Edit: Realized Necklace of Fireball (https://roll20.net/compendium/dnd5e/Necklace%20of%20Fireballs#content) and an NPC spellcaster with a CR2 and has 3rd level spells, and of course the Archer Theme are both a thing! Edited my post to include this. Themes are basically premade adjustments of various offensive and defensive CRs based on what kind of opponent you are going for. It's a pretty cool system.