The basis for this month's post references last month's: I'm a green DM. As much as I try to pursue interesting, novel RP & Exploration encounter designs, deep down I can't deny the allure of a big beefy boss monster. I love them.
This is why I'm a HUGE fan of the Dark Souls games, along with any game that prioritizes the epic feeling of a boss monster. There's nothing like rising to the seemingly insurmountable challenge of a boss that has curb-stomped me so many times that my save file is starting to chafe. And therefore there's nothing I love more than trying to homebrew the perfect boss encounter.
Of course D&D is a very different animal in that regard. Part of the expectation of Dark Souls is that you will die, but that dying won't ruin your ability to interact with the game. Unless your table is all about the meat-grinder play style, that expectation doesn't translate to a tabletop roleplaying game. Dying can be tragic and disheartening for players who have invested so much time and energy into their characters, and in the case of a TPK it can literally bring a multi-year story to a screeching, unsatisfying halt. So how can we design a satisfying boss monster that feels epic and challenging but doesn't require death.*
* An important caveat: for many, myself included, the threat of character death makes the game more fun. Character death might not be common, but it should be possible. The stakes should feel real, otherwise the illusion breaks and the conflict feels hollow. Knowing that the heroes might not survive makes the story so much more exciting, I think.
Step 1 - Identify Party Strengths & Weaknesses
What is your party good at?
Are there (fun) ways to prevent them from doing those things?
What are your party's weaknesses?
Are there ways to exploit those that create challenge rather than frustration?
Answering these questions is by no means formulaic, especially for a game as complex and diverse as Dungeons & Dragons. So rather than try and present a generic path towards answering them, I'm going to give you some insight into how I answered those questions for my home group, how those answers informed the creation of a boss monster, and then a post-mortem on how that design did and didn't work.
The level 18 party in my home game is comprised of...
a Hunter Ranger (hoard breaker, evasion, and whirlwind)
a Cavalier Fighter
an Evoker Wizard (who constantly brings a simulacrum)
a Way of the Long Death Monk (with some cool gloves that let him heal)
an Inquisitive Rogue + Oath of Watchers Paladin multiclass
As for the questions...
What is your party good at?
Hitting and Evading. With a bevy of magical weapons and armor at their disposal, the party functions primarily by maintaining constant damage while avoiding as much damage as possible. The evoker specializes in fire and lightning damage, constantly burning down enemies while never having to worry about friendly fire. Among the other four (whose average to-hit modifier is +14) the lowest AC is 19 (ranger and fighter when not using a shield). The monk has AC 20 and the rogue has AC 24, as does the fighter when using a shield. Of the 5 PCs, 3 of them have evasion and the fighter has a Ring of Evasion, making Dexterity saves a futile endeavor.
Are there (fun) ways to prevent them from doing these things?
Arguably no. Part of the design philosophy of 5e is that hitting is more fun than missing, so the system assumes it will happen more often. And arbitrarily cranking saving throws higher on monsters just to avoid AOE damage spells can feel discouraging. But, at least in theory, missing and having monsters succeed on saves is only frustrating when it is a constant. Occasionally going up against a superior foe, one that is tougher to hit and damage than your usual enemy, can create interesting drama. One way of thinking of it is what I like to call the "oh sh*t moment" - that moment when a player knows that they have stepped into a much greater challenge than their usual encounter.
End Result. A monster with high AC, defenses against the two standard evoker damage types, and plenty of attacks with solid to-hit bonuses.
What are the party's weaknesses, and are there ways to exploit those that create challenge rather than frustration?
Rarely do PCs have true "weaknesses". Instead you have to try and find those patterns in their play that have become second nature to them and see if you can make a weakness of those patterns.
My party, for example, have very few means of flight. And the one with the most consistent ability to fly, the wizard on her broom, also has the lowest AC. Giving a creature the ability to fly out of reach (or into reach in the case of a wizard) while still pumping out damage will force the fighter and monk to find other ways of engaging with the fight.
Meanwhile the rogue/paladin's Aura of Protection has created a tendency for the group to clump up so they can maximize their already powerful saving throws. Using area of effect spells or powers, especially ones that target non-Dexterity saves, can put a lot of pressure on their health pools that are typically safe behind their strong ACs.
Also with several members having resistance or immunity to poison and other elemental damage types, finding other means of "debuffing" them is essential to creating challenge. While the wizard technically has remove curse in her spellbook, I know that she rarely prepares it, instead preferring to leave "healing" to the monk, rogue/paladin, and ranger. Curses can create a stubborn debuff that adds to the sense of challenge while emphasizing an oft overlooked wizard spell.
End Result. A hovering monster with ways of penalizing clustered-up positioning and also some curse mechanics.
Step 2 - Implement Those Answers
So a hovering, hard-to-hit, heavy-attacking, curse-distributing boss monster.
hey, remember when I said I like Dark Souls?
I love this fight from Dark Souls II so much. It's a great introduction to the game's boss fight expectations and is queued up by a fantastic cut scene. So, how does this creature implement the answers we came up with before?
26 AC. Even with the party's largest attack modifier of +15, that's only a 50% chance to hit. On top of just missing a lot, it also means that features like Great Weapon Master and Sharpshooter won't be as effective, so damage output from the martials will be much, much lower.
Improved Parry & Fortified Shield. Being able to once-per-round say "no" to a particularly high roll and also having a 20% chance to negate crits, combined with a chunky health pool and decent (legendary) saves, will make sure this bad boy stays around long enough to be a threat.
Hover Speed & Relentless Pursuit. The hover speed being limited to 20 feet is pretty wimpy, but combined with Relentless Pursuit it can serve the purpose it needs to: move around the battlefield safely (no cavalier AOO's) so that it can pressure the most vulnerable target.
Cursed Lunge. A combo of AOE damage and a pretty nasty curse that only has to hit once to get some really good utility out of it. If multiple PCs fail the save, it can really put pressure on them to start taking defensive actions instead of offensive ones.
Fire Forged Armor & Fire Immunity. The fire immunity represents the creature's Fire Giant past-life while also forcing the wizard to stick to her arguably strongest damage type (lightning elemental adept). But even if she hits with lightning, that will still create a complication in that it will punish anyone in melee. All that friendly fire the evoker is typically preventing is now coming back in a fun, thematic way.
The Equipment. This is how I was able to justify the massive AC and to-hit modifiers without the creature being a loot drop to an already kitted out party. I love using human-bane on bad guy stuff since it can give you extra damage but isn't a bonus that PCs can utilize as easily. This is also a huge creature, so none of the gear can be used by a medium sized creature without some super cool magic to help resize things (this is partly just me really really wanting to make a 5e port of Pathfinder Giantslayer :P ).
All of this combines together to create what should be a powerful, challenging, thematic boss battle that not only references a video game that I and many of my players enjoy, but that also serves as a cool foil to the party's usual tactics.
But a creature that is only powerful can also be incredibly lame. Allowing your PCs chances to figure them out and find clever ways to counter-play is also part of a satisfying Dark Souls-esque boss. So what are the weaknesses of this monster?
Lack of Constitution Save Proficiency. Sure, +9 isn't anything to sniff at, but it's not a guaranteed success either. With a standard level 18 save DC 19, that's a little better than a 50/50 shot at success. Leaving one standard save weak opens the door for more unusual spell selections, as well as...
No Stun Immunity. Here was the real trick. One thing about our specific monk's playstyle, being Way of the Long Death, is that he likes to reserve a lot of ki points for Diamond Soul saves he knows are important and also "ki tanking" damage that would put him to zero HP. But this thing is a beast, and with magic resistance and legendary saves, it was unlikely traditional crowd control effects were going to work. By leaving room for Stunning Strikes (non magical Con saves), it meant that he would have a good thing to spend ki on to possibly turn the tide of battle.
Cursed Being Trait. I love niche, thematic counter-play. Allowing spells like remove curse and greater restoration to be used offensively would mean they weren't wasted if Cursed Lunge wasn't hitting, and would also create a cool moment unique to this fight.
Relentless Defense. This is a powerful ability that could mean multiple chances at avoiding high attack rolls by recharging its Improved Parry. However, it has to do the attack against the same creature that caused the Parry reaction. This meant that if it tried to get multiple parries against melee combatants, it would leave itself vulnerable to ranged attacks (which the party had plenty of between the ranger and throwing-knife rogue).
Undead Creature Type. Smites. Full stop.
Step 3 - Run It!
Now that you have your awesome monster, use it! And also make note of the things that worked well and didn't work well. I know that when I was looking at this statblock before the fight, I started to question if I'd truly lost my mind. Was it too punishing? Was it not going to be fun? Would it be a TPK prompted by a reckless night of wanton hombrew!?!?
Well I am happy to report that while it did nab a kill (thanks to the curse effect no less!), it was thankfully not a TPK. And the kill was quickly undone by a wish resurrection the next day.
So, having used this statblock in a fight against a well equipped party, what were some lessons learned?
"There's no save!?" Skewer can catch players off guard since it has no save. Personally I like it, and I think more abilities should eschew saving throws when the damage or status effects they inflict aren't debilitating. Prone can be tactically rough, but 4d6 bludgeoning isn't terrible and prone is instantly taken care of on their turn.
Unused Spells. When I designed the spellcasting trait for this creature, the intent was to buff their combat abilities with some cool magical effects (like spirit shroud) while also providing nifty answers to specific party tactics (wall of fire to mitigate ranged damage dealers or grouping up; dispel magic to possibly one-shot a simulacrum). However, I never used a spell with a casting time greater than a bonus action. Part of this was due to the prevalence of counterspell in the party, but it was also because sacrificing three massive attacks just to cast a single spell never felt worth it. If I were to tweak this, I would change the multiattack action to allow for a single spell cast plus one melee attack.
No Normal Legendary Attack. This one I actually modified on the fly to include in the fight. Since Skewer required 2 legendary actions and Relentless Defense required the use of Improved Parry first, I often found myself with turns ending and not wanting to do anything (or nothing else I could do). That gave the PCs time to move around and took pressure off of them without additional damage happening. Halfway through I improvised a single attack legendary action to help keep the fight tense.
26 AC. Here's where I thought things would go off the rails, but they didn't! At the beginning there were definitely a fair share of misses, and the Improved Parry was proving to be a thorn in the ranger's side. But around the half-way point the PC's dice got hot and I actually found the creature's health to be falling dramatically. I don't think buffing the AC is the answer here - it was more of a good feeling knowing that a super outlandish AC like this isn't so game breaking as to be unfun. Still use it sparingly, but it did the job of making things feel challenging.
Alternative Legendary Resistance Usages. This is something I've been thinking about incorporating for all my creatures with Legendary Resistances anyway, but this fight made it painfully obvious that it was needed. Once the PC's dice got hot and the HP starting getting blasted away, I found that I still had all three Legendary Resistances and nothing to really use them on. Between solid save bonuses and magic resistance, I wasn't failing against any of the evoker's damaging spells. And she didn't pivot into more crowd-controlly tactics, fearing that the undead nature would prevent a lot of the usual status conditions. This was another on-the-fly fix: whenever the Pursuer's hit points would have been reduced to 0, they could spend a Legendary Resistance to regain 50 HP. Fifty isn't that much against a high level party, but with 26 AC it was enough to keep the fight going and dramatic.
Overall this was a super fun fight. It hit all the high-notes I wanted it to and helped me become a better Green DM for later.
If you use this big baddie for your games, let me know what you think!
Happy Boss Battles!!