Anatomy of a D&D Campaign: When a Boss Fight Goes Terribly Right

Anatomy of a D&D Campaign is a periodic look at the planning of Dungeons & Dragons sessions. We will dig a little deeper into technical elements, with discussions about encounter design, crafting unique monsters, and handling unique challenges that come up at the table.


What happens when a Dungeons & Dragons' battle goes terribly wrong for the players, and how does a Dungeon Master work through the unique issues that pop up when things don't go as planned?

Last year, my friends and I started a short Dungeons & Dragons campaign built around a group of cultists trying to free their dragon god from his prison in the Shadowfell. Meeting about two times a month, the players trudged through jungles and up mountains trying to find three giant nails the size of javelins that were used to seal the dragon away in the first place. Last weekend, the players had made their way to the location of the last nail, which was found in a small underwater temple. Due to the magical forces at work, the ocean had moved away from the temple, giving the party room to operate without figuring out how to breathe underwater or attack foes at a constant disadvantage.

Most of the encounters in this campaign were built around monsters with a mouth motif, as their dragon god was fighting an entity known as "The Thousand Mouths." The players had already faced creatures made of teeth and a giant tongue, so the temple encounter was built around "spit monsters," which were mostly re-skinned oozes and puddings. After battling their way through several sentient balls of spit, the players found the last nail in a small room guarded by a large loogie with a giant shark inside. The nail was inside of the loogie, so the players would need to reach inside of it, pull the nail out of the ground, and then run away.

For the "boss monster," I used the Giant Shark Bowl Ooze found in Kobold Press's Creature Codex. It's a fun and unique monster, one that fit thematically with the storyline and one that was dangerous enough to challenge the players. When starting the encounter, I reminded the players that they didn't need to "beat" the monster, they simply needed to pull the nail from the ground and get away safely. The Giant Shark Bowl Ooze was a CR 8 monster (which is technically a Hard encounter for a group of Level 5 adventurers) but the players were already a bit beat up from fighting the re-skinned puddings earlier in the battle. Once the nail was out of both the ground and the Ooze, the ocean would rush back in and the encounter would move from combat to a series of checks to see if they could get out of the temple and outrace the ooze.

shark bowl
(Photo: Kobold Press)

At first, the fight went pretty smoothly for the players. After dealing out some chip damage to the Ooze and figuring out its range and resistances, the party attempted to push the ooze off the nail so they could just pull the nail out of the ground and run. Unfortunately, the ooze was "fastened" to the nail and couldn't be pushed off of that. After that, the barbarian decided to reach into the ooze and pull the nail out, and that's where things went sideways.

When I built this encounter, I expected that the party's barbarian or paladin would be the ones to pull the nail out of the ground since they had the highest Strength stats. The person who pulled the nail would in essence need to pass two checks: a Strength (Athletics) check of DC 15 to physically pull the nail out of the ground, and then a contested Strength check to pull their arm out of the Ooze. What I didn't expect was that a series of bad rolls would lead to half the party getting trapped inside the Ooze when the ocean inevitably came rushing back into the temple.

From there, the encounter became a series of hypothetical questions that I had to answer quickly as a DM. Would the Ooze maintain its composition once it was underwater, as it was technically a massive ball of spit? And if the Ooze did dissolve, would it dissolve before or after the shark inside did automatic damage to any players trapped inside of it? Would magic reeds that allowed the party to breathe underwater still work when a player was unconscious? Does a giant shark (now freed from his spit ball) prefer live or dead prey as it chased after the party?

These were weird questions, but the answers meant the difference between life and death for the players. I didn't want to go easy on the players, but at the same time I didn't want to punish them because the encounter progressed differently than I pictured. Luckily, there wasn't a time crunch, and my players and I were able to talk through the issues with the help of some Google searches. As the person controlling the Ooze, I decided that the Ooze needed to make a Constitution saving throw every round to see if it dissolved or not. If the Ooze dissolved, any player trapped inside of it wouldn't take automatic damage, but they still needed to deal with the shark inside, which was much more adept at swimming than a giant loogie.

Thanks to Google, I learned that scuba gear could get dislodged from an unconscious scuba diver thanks to involuntary exhalation, so unconscious underwater players had to make an extra Constitution saving throw at the start of every turn to see if they could keep breathing. We also learned thanks to Google that sharks usually prefer live prey to dead prey, so the shark didn't linger after it mauled one player into unconsciousness. That was probably the most critical decision, as it kept two players from dying inside a shark's mouth.


By the end of the encounter, one party member was dead and two others were on unconscious, but the party had successfully dislodged the nail and killed the shark for good measure. The encounter basically came down to the barbarian's final attack, as she successfully hit the shark twice with a greataxe despite making the attacks at disadvantage due to being underwater.

This was a fun encounter (especially since the party's Cleric had Revivify to bring back the fallen Paladin), but it took a lot of mental gymnastics once the fight started. It's a good example of why DMs can't just rely on preparation alone when building an epic D&D encounter.

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