The steps for building a puzzle boss are pretty much the same as building any kind of encounter, or any kind of story, ever. That is:
- Goal: The players want something
- Conflict: The DM puts an obstacle in their way
- Resolution Mechanic: The players and/or characters overcome the obstacle (or fail)
In most combat encounters this is incredibly simple:
- Goal: The players want to go to a place or get a thing
- Conflict: Monsters want to stop the players from going to the place or getting the thing
- Resolution Mechanic: The party uses violence until there are no more monsters
The party could use diplomacy or stealth or magic or whatever tools they want, but the general structure of an encounter is the same. An encounter even uses the same steps from the perspective of the DM, but that’s another post.
What’s important about this structure is that it’s nested. As you drill down into it, you’ll find the same steps repeated over and over until we get down to a game mechanic. In D&D, that’s usually a d20 roll:
- Goal: The players want to kill the orcs in the forest
- Conflict: The orcs do not want to die
- Resolution Mechanic: Combat
- Goal: The ranger wants to use her bow
- Conflict: Bow attacks provoke attacks of opportunity
- Resolution Mechanic: The ranger goes to a place where the orcs cannot reach her
- Goal: The ranger wants the high ground
- Conflict: The high ground is very high
- Resolution Mechanic: Climb check vs. DC
- Goal: The fighter wants to hit an orc with his sword
- Conflict: The orc does not want to be hit
- Resolution Mechanic: Attack roll vs. AC
Most conflicts have fairly straightforward goals, conflicts and resolutions, and that’s important. The key to a puzzle boss is that it doesn’t:
- Goal: The fighter wants to hit the orc with a sword
- Conflict: The orc has a magic barrier around him
- Resolution Mechanic: Disable the barrier
- Goal: The party must stop the barrier
- Conflict: The party does not know how
- Resolution Mechanic: The party makes skill checks, or tests theories, or thinks really hard, etc.
The puzzle is in figuring out how to resolve the conflict. It’s not a matter of what the best answer is (for example, swords versus clubs versus fire) but how to answer it at all. The simplest way to do that is to make direct, obvious combat either impossible or just a very bad idea, but there are several ways to go about it.
Puzzles are too broad to have a clear set of creation steps. They’re not like a monster or a trap where you can say “this type of puzzle is this difficult, and it takes this long, so it has this Challenge Rating”. It’s more of an art, where you have to balance the combat, the story, the players, the schedule, and the mood at the table as it shifts. But like art, while there aren’t rules there are strongly-worded suggestions:
The party has to discover the puzzle quickly. Combat has certain expectations in D&D, and one of those is that it can be resolved via combat mechanics. Breaking from that is fine, but breaking from it in secret and expecting the players to read your mind is not. You don’t want your players to miss the runes on the floor and spend four rounds trying to hit the invincible necromancer with a sword. They’ll rightly consider it a waste of character resources and real-world time.
The answer can’t be too obvious. Things like “kill the healer first, or he’ll heal his allies”, or “the wizard has terrain advantage” aren’t puzzles, they’re complications. They’re a good way to make fights more interesting and dynamic, but that’s not what we’re talking about here. You have to escalate the difficulty until the players don’t have a evident answer. Consider “kill the healer first, or he’ll heal his allies, but everybody is acting similar so we need to find out who the healer is”, or “the wizard has terrain advantage because she’s on a ledge with no visible access point.”
There should be more than one answer. If the puzzle relies on an arcane leap of logic or an absurdly specific action, there’s too strong a chance the players won’t solve it at all. Continuing the above examples, if the party can only find out who the healer is by remembering that all clerics of the healing god have a small brand on the back of their neck, or if they can only make it to the wizard by throwing paint at the wall to reveal the hidden ladder to the ledge, that’s a bad puzzle. The key word is “only”. Both of those are fine answers, but when you reject other plausible answers because they’re not the one you had in mind, the puzzle you’re actually giving the players is “guess what the DM is thinking”.
You need to accept that the players are going to try something else, like using detect magic to find the telltale signs of a healing or illusion spell. Reward them for ideas that fit with the puzzle you’ve presented. I usually require that an answer have at least two of the following traits: it’s clever, and it shows the players are really thinking about their situation; it’s entertaining, and it gives us joy to see the characters try it; and it’s successful, because the players rolled high or set things up well enough that a roll doesn’t matter. A few examples:
- A player suspects the enemies all worship the same god, but asks if their holy symbols are the same. With a good Perception check she notices (or declares) that they’re subtly different, and asks to use Knowledge (religion) to recall whether those symbols indicate different religious disciplines. This is clever because she’s considering and manipulating the backstory of the enemies and she rolled well enough to be successful, so she learns that only one enemy has access to healing magic.
- The fighter can’t get to the wizard’s ledge, but he knows it’s attached to a wall. He starts attacking the wall, trying to bring it down. The party asks him to stop because it might destabilize the architecture of the rest of the room, but he persists and starts rolling damage. This is entertaining because it can add a dynamic element to the combat, and with good damage rolls he can actually break through a wall. It also helps that I have a soft spot for players who hurt themselves to fit their character, so if the fighter is a berserker who loves destruction despite the party’s comedic exasperation, I’d consider that entertaining.
- The party decides to stack themselves on each other’s shoulders so the rogue can climb them and reach the ledge. That’s a clever use of party resources (time) and mechanics (carrying capacity, height, and weight), and it’s entertaining enough that I want to see it happen. If I’d ask them to make rolls at all the DC would be very low. I might give myself a bonus to attack players at the bottom of the pole, but that’s unlikely to impact the success of their maneuver.
Per the above examples, “entertaining” usually means “funny”. But it can also mean “dramatic”. A player who uses a forbidden spell, sets aside their code of honor to do something underhanded, or sacrifices themselves so their allies have a chance, and who’s willing to accept the narrative fallout of their decision, deserves success as much as somebody who’s trying to pick up an enemy and throw them into another one.
Have a purpose for the puzzle. The puzzle needs to fit in with the pacing of the campaign and the story the campaign is telling. Having a puzzle boss because “it’s time for a puzzle” isn’t a sufficient reason. It should happen during a battle where it makes sense that just hitting the opponent isn’t a complete solution. Often the best way to do that is to telegraph it in some way; if the players find out this group of fighters has never had a single casualty, they won’t be surprised when they see it’s because they have a hidden healer. The party goes in expecting something out of the ordinary and they’re mentally prepared for it.
In addition, the puzzle needs to work with the boss itself. The powerful orc warlord with a reputation for ripping his opponents limb from limb is not going to hide behind his defenders and take potshots with a crossbow. He’s going to wade into battle with supernatural fury, and it’s up to the players to find out why their blows are bouncing off his skin. This is a good place to toss in a plus or a minus; the warlord is all but immune to the barbarian’s axe and it falls to the sorcerer to notice the warlord’s necromantic aura and realize he’s actually a zombie powered by a magic item. A clever player might even swing their role as a minus into a plus, like the barbarian who realizes her axe isn’t working, drops it, and grapples the warlord to mitigate his attacks and buy time for everybody else. That’s a good kind of clever, even if it does mean I have to find my grappling flowchart.
Make it fun. This suggestion overrides everything else. A puzzle can be well-balanced, creative, and narratively meaningful but still be a tedious slog. If the party just has to pull a lever every round to keep poison gas from filling the room, all you’ve done is give them an action tax. There’s a difference between “I can’t believe we did it!” relief and “I’m so glad it’s over!” relief, and that line can move based on your campaign, your players, what happened last week, how tired the players are from work, and so on. One of your roles as a DM is to focus on the right thing: puzzle bosses, like everything else in the game, are a means for having fun. If yours isn’t fun, it’s wrong.
If you’re looking for a detailed breakdown on types of puzzle bosses, you’re out of luck. I don’t have one either. But I can recommend the following works that have some examples I’ve used myself, as further reading:
- Jojo’s Bizarre Adventure – Starting in the third arc they get into the concept of “Stands”, which allow the main characters to fight with supernatural, usually external entities. Most battles boil down to “Who is my enemy, what is his power, and how do I survive it and punch him in the face?”
- World of Warcraft – I’ve gotten a lot of ideas from browsing strategies for raid and instance bosses. The numbers don’t really mean anything (I don’t know if “3000 Nature damage” was meaninglessly low or an insta-kill in the relevant expansion) but the general ideas are good for keeping fights dynamic and adding an element the unknown.
- Final Fantasy – Each game has several bosses that don’t fit the normal “grind and smash” mold. I’m told the single best game for this is the remake of Final Fantasy IV for some recent portable system, where almost every boss is an actual challenge because they each need a different strategy. Games that let you change your party, like Final Fantasy Tactics, may also work for general ideas, but I’m legendarily terrible at strategy games so I don’t have a ton of experience here.