D&D 5E Need some good "guardian" monsters for a treasure vault (4th lvl group)

[Delandel]

Backstory:
Rune's Hollow used to be the headquarters of the Thunderaxe clan, wild dwarves running a profitable business in the mountain ranges of Chult. Their treasure vault was stored safely here, a gathering of untold riches, with a powerful artifact called the Myststone as the cherry on top. Rumored to be a fragment of the dead goddess of magic, Mystryl, the Myststone had the power to imbue mundane items with magic, and is said to have been the superior prototype to the mythallar constructs and the Spellforge in Phandelver. These priceless treasures were hidden away in a secret section of Rune's Hollow, protected by vicious guardians to ensure the clan's treasures remain safe.


During the events of the Spellplague, massive earthquakes caused Rune's Hollow to cave-in, and blue flame flared up deep within the mountain, incinerating nearly all the inhabitants. The survivors fled for their lives. Hundreds of years later, when the calamities of the Spellplague finally settled down, kobolds now inhabit the ruins of Rune's Hollow. However, the treasure vault -- and its guardians -- remain hidden and intact.






I'm looking to build a sweet encounter for four characters of 4th level. I need some guardian(s) that will protect an ancient dwarven treasure vault. The dwarves would've spared no expense to keep their treasure safe. Any suggestions for what could be suitable guardian(s) would be greatly appreciated as my brain is currently running blank!

 

[Astrosicebear]

Without seeing the creatures in the MM and only going by CR, it would depend on what kind of forces you are talking about? A whole dungeon ecology? or just the forge guardians.

[RETCONNED]

Maybe a Barbed devil (Cr5) should be a strong, tough encounter as a boss. A room with some Mimics (CR2) would be funny. A skeletal Minotaur(Cr2) with a Mummy (Cr3) might be neat.

 

[Sacrosanct]

Sometimes when I am looking for inspiration, I look to real life animals. Because sometimes truth is stranger than fiction

In this instance as you describe, a caved-in lost mine and tunnels? With a clan of kobolds? I might go with a giant version of the horned spider tail viper



GIANT HORNED SPIDER TAIL VIPERHuge Beast, unaligned

Armor Class: 14 (natural armor)
Hit Points: 76 (8d12+24)
Speed: 40ft

STR: 18 (+4), DEX: 16 (+3), CON: 14 (+2), INT: 7 (-2), WIS: 6 (-2), CHA: 6 (-2)

Senses: darkvision 60ft, Passive Perception 13
Skills: stealth +6
Saving Throws: Dexterity +5, Constitution +4
Languages: --
Challenge: 4 (1,100 XP)

ACTIONS
Bite. Melee Attackc: +8 to hit, reach 5ft, one target. Hit: 14 (2d8+5 piercing damage). DC 12 Con saving throw or take 10 (3d6) poison damage and target is poisoned

TACTICS
Snake remains hidden, using its coloration and rough scales to blend in near perfectly among the rocks and stone. It leaves the tip of its tail exposed, twitching it like a large spider (2' in diameter). When a creature comes to investigate it, it moves the "spider" away, skittering into the darkness. As the prey gets closer, the snake strikes.

In your scenario, the snake hunts the kobolds. If you want to make it more of a fantasy creature, you could turn the spider tail into something that looks like a pile of gems or something.

 

[Sacrosanct]

Without seeing the creatures in the MM and only going by CR, it would depend on what kind of forces you are talking about? A whole dungeon ecology? or just the forge guardians.

For the latter, the guardians of the treasure so to speak, CR7 Shield Guardians would work. Maybe a bound CR8 chain devil. Earth elementals are CR5, maybe a few of those. Unless you go crazy and explain a Mind Flayer CR7 with an Umberhulk CR5 thrall.

Remember, in 5e, a CR X creature is supposed to be a challenge for a party of four X level PCs. So a CR 7 creature (especially a few of them), would destroy a party of four 4th level PCs.

 

[jadrax]

I must admit I am having a disconnect between 'The dwarves would've spared no expense to keep their treasure safe' and '4th level party'.

Maybe some sort of malfunctioning Iron Golem that was pretty boss when the Dwarves created it, but is in bad need of repairs?

Failing that, the Challenge 3 Spectator is always an option.

 

[Astrosicebear]

Remember, in 5e, a CR X creature is supposed to be a challenge for a party of four X level PCs. So a CR 7 creature (especially a few of them), would destroy a party of four 4th level PCs.

Ah yea, these would destroy them at 4th. My bad.

 

[Delandel]

Without seeing the creatures in the MM and only going by CR, it would depend on what kind of forces you are talking about? A whole dungeon ecology? or just the forge guardians.

For the latter, the guardians of the treasure so to speak, CR7 Shield Guardians would work. Maybe a bound CR8 chain devil. Earth elementals are CR5, maybe a few of those. Unless you go crazy and explain a Mind Flayer CR7 with an Umberhulk CR5 thrall.

Just forge guardians. My initial idea was the dwarf clan put a security measure to make sure thieves couldn't break into their vault, or if they were under attack, their security would hold off any looters long enough for them to regroup and repel the invaders. It could be physical monsters, could be a puzzle, anything really.

I love your suggestions, by the way. How unfortunate that the MM isn't released yet. At least I can "update" their 3.5 versions. I'm leaning towards earth elementals currently.

I must admit I am having a disconnect between 'The dwarves would've spared no expense to keep their treasure safe' and '4th level party'.

Maybe some sort of malfunctioning Iron Golem that was pretty boss when the Dwarves created it, but is in bad need of repairs?

Failing that, the Challenge 3 Spectator is always an option.

Perhaps I should leave that detail out. My intention with that is they are willing to spend lots of gold on zany ideas, not necessarily use their gold efficiently.

I never got to use a beholder on my PCs. It's a pretty classic monster. Spectator could be a fun alternative!


[MENTION=15700]Sacrosanct[/MENTION]: That viper looks fantastic. I wouldn't use it for the guardian of the vault, but they will be journeying around the ruins of the mine, so it would make sense that they could stumble across this snake's lair. It picks off wandering kobolds but the PCs would make for an even better feast.

 

[Astrosicebear]

I love your suggestions, by the way. How unfortunate that the MM isn't released yet. At least I can "update" their 3.5 versions. I'm leaning towards earth elementals currently.

I mis calculated the CR for a 4th level party, so see my revised post. Those CR7s might destroy them. An elemental would be pretty tough, maybe deadly, depending on how weakened they are.

 

[Tormyr]

How about the Flameskull from the Basic DMG? It is CR4 and its flavor text specifically states that it is placed to guard treasures and the like.

Just to reiterate, the CR of a monster is now an indication of what is the earliest level you can introduce them to the party. Adding them before that could lead to several one shot takedowns of the PCs. Just a couple of days ago, a I had a Giant Crocodile (CR5) come within 1hp of knocking the level 5 rogue from full hp to unconscious with 1 bite attack.

 

[drjones]

As a general adventure design thing I'd be a little wary of the solo boss style encounter. Some classes are quite good at putting the whammy on a single bad guy without legendary abilities. Lean towards one biggie with the option to spawn/bring in more fodder or mid range trouble if the fight turns into the PCs whittling down HP while the big baddie is neutered. Until the DMG it's probably best to leave yourself room to adapt the difficulty on the fly.