Making solo boss encounters difficult...was it always so obvious?

[MrFahrenheit]

So I've been DMing 5e for a year and a half now, and had solidly come to the conclusion some time ago that "boss monsters" in this edition are meant to be encountered with minions.

My most recent session showed me this wasn't necessarily the case. Simply put, not giving the party time even for a short rest will make the boss monster encounter feel significantly more boss-ish, without throwing in minions.

The run-up encounters weren't all that taxing, either. For reference, the party is mostly level 15, with a couple 14 stragglers (the battlemaster who leveled up during the session, and the druid). A couple high-level smites used up by the paladin, some mid-level slots used by the cleric, sorceror and bard, one of the wild shapes used by the moon circle druid (as well as some mid-level slots), and two of the battlemaster's maneuver dice are what was used up. Suddenly, the boss fight became far more challenging. Not deadly - there were no PKs - but certainly taxing.

So I guess my reflection on it was, as the subject line stated...was it always so obvious? But more importantly...aside from throwing a vastly higher CR vs the party, is there any way to have a fresh/well-rested party vs solo boss fight that doesn't rely on the latter employing minions to make the challenge feel appropriate?

[Socratov]

Well, it not hard to create a single boss enoucnter, but the ability to overshoot or undershoot the challenge is considerable. It's very simple: it has all to do with action econopmy. If you are, say, a part of 5, you have 5 actions each round (maybe more depending on action usage, bonus action usage, class features etc.). As a boss, you have 1. I have skipped 4th so I can't speak for 4th edition, but in 3.5 this was blindingly obvious and the reason why monsters explicitly were able to attack in multiple ways or could take multiple actions per turn (or summonned minions or something). To hit the sweet spot in between too hard and too easy is for 5e similar to 3.5e.

[Alcibiades]

To add to both Socratov's post and reply to OP's question:

Take a look at the Angry GM's Paragon (http://theangrygm.com/return-of-the-son-of-the-dd-boss-fight-now-in-5e/) monsters. He proposes treating those boss monsters as two creatures merged as one: It has double hit points and two turns per round in the initative (the 2nd one disappears when it's reduced to half HP) so as to combat the discrepency in action economy.

[MrStabby]

You can balance single monsters but if you do it regularly you end up reusing a lot of tricks so encounters can begin to feel the same.

A few things I did use:

Surprise. A few PCs skipping their actions on the first turn of combat makes a big difference.

Using the lair/legendary actions type setup from the MM.

Spells or attacks that impact multiple players - whirlwind attacks, AoE spells.

Mobility. Have the boss use speed and reach/range to only engage part of the party at once. Also use corners and blocked fields of view to limit number that can reach them.

Hostile environment. If PCs are trying to avoid pit-traps, choking on smoke, and dodging streams of lava then it is a bit more than a fat lump of HP vs the world.

[EvilAnagram]

I've constructed a port of the 4e Skull Lord designed as a solo boss encounter, and in addition to some of the suggestions mentioned (multiple attacks, AoE, legendary actions) I've developed some other strategies.


Multiple Stages: The 4e Skull Lord had relatively few HP, but every time he was reduced to 0 he regenerated completely and list one of his three skulls. This means that while he only has a total of, say, 180 HP, every time he's killed a portion of the damage is completely lost, mitigating the effectiveness of novas.
Unpredictability: At the start of the first stage, he casts Blink as a legendary action. This allows him to negate rounds of character actions without costing him his own action and allows him to attack without letting the characters know where he's coming from.
Auras: At the start of the second and third stages, he casts Flame Cloak and Anti-Life Shield, respectively. This forces the players to treat each stage as almost entirely separate battles and reduces the effectiveness of some strategies.

[Fflewddur Fflam]

This is a side-note to this conversation but Dragons are just too wimpy in 5e. They all should be sorcerers and they all should be resistant to non-magical damage, for starters.

[Joe the Rat]

It's not just more actions, but being able to spread those actions around..
Multiattack helps some, but Legendary actions really add to any big boss, and somewhat rebalance action (and elicit that wonderful"oh crap" moment the first time it acts off-turn).

[Isidorios]

This is how I boss fight.
https://s10.postimg.org/yaob2m4m1/Octopus_with_swords.jpg (https://postimg.org/image/94ncvs3bp/)capture screen (https://postimage.org/app.php)

[Gastronomie]

This is how I boss fight.
https://s10.postimg.org/yaob2m4m1/Octopus_with_swords.jpg (https://postimg.org/image/94ncvs3bp/)capture screen (https://postimage.org/app.php)I've found this sort of strategy to be actually pretty effective.

It's already been mentioned about Paragon monsters, but to add on to that, I suggest you give the boss a certain level of mobility with wing blasts, flyby, bonus action disengage, and stuff along those lines. That, and/or a good number of ranged attacks and AoEs. Otherwise he will be able to attack only those who first come around him and threaten him with opportunity attacks (the frontline martials).

[Isidorios]

snip

Haha, you should have snipped!

As to that Octo fight, used a multi-level Piazo ship map.

After getting aboard ship trapped on rocks at edge of maelstrom:

Top Deck: Giant Crabs and Giant Crab Alpha

Second Deck, traps (set by Paragon Octopus for crabs), tentacles through the floor with swords.

Cargo Deck (Paragon has used potions from chest to recover arm damage), Traps, hanging sailcloth to obscure LoS, party must seal chest (or steal potions) while fighting Octopus (who has a parry reaction for each arm!