D&D 5E Need help for complex encounter: Gates of Firestorm Peak.

[Ancalagon]

So. My players are about to enter the classic late 2e dungeons, The Gates of Firestorm Peak.

https://en.wikipedia.org/wiki/The_Gates_of_Firestorm_Peak

SPOILERS AHEAD!

Now, at the very entrance the PCs must force their way through a gauntlet of duergar who have been ordered to keep out all intruders. They are ready for a fight. These Duergar have seeded the area with invisible caltrops, are themselves invisible (but not improved), have cover from walls, have long polearms *and* are enlarged to huge size, giving them 20 foot reach.

This "gauntlet" can be seen here: http://dmdavid.com/wp-content/uploads/2014/07/Gates_of_Firestorm_Peak41.jpg

The entrance is on the left. There are 2 groups of elite duergar dwarves with the pole arms - 4 directly guarding the entrance behind the first spiked wall, and the second in the "enclosed" rectangle of spiked walls, with about 30 hp each. There is a third group about midway of somewhat smaller/weaker (only large) duergars having formed a pike wall formation These are cannon fodder, with 10 HP each. Should this formation be breached, there are 2 more sets of spiked wall with more pike wielding duergars behind them. (10 veterants with 20 hp each)

I have a lot of rule-related questions here, as how I should translate these rules from 2e to 5e, and how to "run" the fight so it's challenging but fun.

1: Enlarging and reach. 2e Duergars were bad-asses, and I've ruled that these Duergar are warped by the local eldrich energies and thus are a bit "more" than the 5e equivalent, so their enlarge is much more powerful. However, I need some help/advice on how to rule it.

Damage wise, the adventure says that their damage is multiplied by 3 (!), but said damage is only 2d4. This result in a hard hitting - but nowhere giant-strenght - 6d4 points of damage (the weaker duergar do less damage). Furthermore they only have one attack.
What is troubling me more is reach. In the original adventure, that's 25 feet - meaning that there if a lot of the battle field where a PC can be hit by several polearms coming from all directions! However, I'm having the hardest time figuring out the reach of larger creatures in 5e. I see giants have a reach of 10 feet (except for the stone giant which has a reach of 15 feet for some reason).

Does the damage seem reasonable? Any comments on the reach?

2: Attacks of Opportunities: No matter the exact area the creatures can reach, it's clear there is going to be a lot of potential for AOO. In 3e this would have been almost paralyzing (I can't remember for 2e, sorry!). However in 5e there is more freedom with moving around threatened zones, although perhaps not as much since there will be a lot of "edges" of threatened areas. Are there special rules for AOOs and polearms in 5e that I should know about?

3: To hit numbers: To hit numbers have gotten better in 5e - the duergars had thacos of 17 and 19 (ie, +3 and +1 to hit). I definitely am going to have to increase that, but this may make the encounter *very* deadly as many pike hits are likely... This leads to a question about numbers - there are a *lot* of foes here (by my count, 26 total) and the party doesn't have fireballs.

4: Cover: The 15-16 feet tall enlarged duergars are fighting behind a 10 feet tall wall. That should provide cover bonus right? Should it be even possible for a character at the foot of the wall to this them?

Any and all advice is welcome

P.S. Lastly, because people will ask, the party, all level 6

Half-elven Oath of the ancient paladin with high AC but ok-ish HP (12 con), the party tank
Slugman cleric, knowledge domain
Human warlock, tome, elder ones patron
Human Monk of the open hand.

The party will be assisted by a human rogue (won't be doing much but distractions etc) and one TINY SERVANT lantern provided by an NCP mage with the dragon breath spell (3d6 damage cone)

 

[Ancalagon]

No one? Not even a comment about reach? :/

 

[Schmoe]

IIRC, there were no AoO's in 2e. There were also no readied actions by RAW. So despite the impressive reach of the Duergar, it wouldn't have been nearly as formidable in 2e as you might think, and clever use of illusions, invisibility, etc. could really reduce the threat from all of those halberds. I wouldn't try to recreate AoOs or readied actions in this scenario without carefully thinking about the impact. Unfortunately I can't help you about the 5e specifics.

 

[Lidgar]

IIRC, there were no AoO's in 2e. There were also no readied actions by RAW. So despite the impressive reach of the Duergar, it wouldn't have been nearly as formidable in 2e as you might think, and clever use of illusions, invisibility, etc. could really reduce the threat from all of those halberds. I wouldn't try to recreate AoOs or readied actions in this scenario without carefully thinking about the impact. Unfortunately I can't help you about the 5e specifics.

IIRC, this module was released after the Players Options 2e supplement came out, which first introduced reach, facing, AOO, etc. So I think the module was trying to introduce those concepts into encounters.

For 5e, I really do not get to hung up on rules mechanics, but error on the side of what sounds fun/challenging for the PC's.

I'd go with 15' reach, and maybe reduce the number of duergar. Damage looks fine.

I'd say they all have half cover:

A target with half cover has a +2 bonus to AC and
Dexterity saving throws. A target has half cover if an
obstacle blocks at least half of its body. The obstacle
might be a low wall, a large piece of furniture, a narrow
tree trunk, or a creature, whether that creature is an
enemy or a friend.

 

[Ancalagon]

This really brings me back, to the days where mooks had +3, +1, or even +0, to hit (to translate thaco in "modern" values). Now with most foes having *at least* +4, you really have to be careful with the numbers of said minions. Going from +1 to +4 can easily double the number of successful enemy attacks...

I think I will change the "rear" guard - either the pike wall or the guys at the rear. They are weaker but the PCs will already be hurt at that point.

 

[Coroc]

I think if i remember it right 2e had aoo but only if you moved out of the reach of a mob. I might be wrong eventually, but i am 100% sure even the early goldbox games had that mechanic and they were partially 1e.

On your Problem: If they hit hard make them squishy. 10hp is nothing in 5e. 30hp is something.
Do not give them polearm mastery which would allow these AOO.
Balance it for your specific Party.

Dwarfes in my Point of view have high hitpoints and medium to high armor, so if you want them to be Feeling like dwarves you might think about lowering their damage Output. It will be hard enough for casters in your Party to maintain concentration.

How does the Party fight? Do they go all out dpr or do they buff / debuff /evaluate a Scenario and seek for tactical advvantages / have any means to Scout ahead invisible etc. That all has to be taken into account. A single wizard familliar capable of hiding or turning invisible or going undetected ( a rat e.g.) might Change the whole Thing.

Charm spells can create havoc. Area effect spells can trivialise things. What Level is the Party?

Come over with more Detail info pls if you want real advice.

 

[Dan Chernozub]

Ugh man, I love complex encounters.

First, I want to figure out what do you want, as an encounter designer, for your players to experience. So far I get the impression that you are spending too much effort reworking the old encounter to the new reality. My recommendation would be to scrap it and rebuild from scratch. Keeping the original in your mind, obviously.

Also, I would suggest thinking about how those Duergar think - intelligent enemies should feel intelligent, IMO. Well if your players like slaughtering the monster zoo, it is another story, obviously.

1. Plan. How are the Duergar planning to defend? What are their tactics? Do they, using the invisibility let the attackers wonder in and then attack from advantageous positions? But to do this they have to be forewarned of the attack? What warrants calling the reinforcements? Do they have a fall back plan or do they fight to the last man? Do they prefer to kill, capture or drive off the attackers?

2. Terrain. Mechanical things regarding the staff the enemies are going to use. Not necessary to have the exact numbers by this point, but a general idea of the effects of staff and most likely interactions that the PCs can have with them (how climbing/breaking the wall works, can the invisible caltrops be swept away with some spell etc. - based on what your group has at their disposal).

3. Enemies. IMO fighting wave after wave of duergars#316 of various levels of eliteness is less exciting than fighting Duergar guards and their specialists/spellcasters/commander. It also feels logical for LE intelligent guard post to have someone in command. Special abilities and how are they going to use them is what is going to affect how the encounter plays out the most, so this should be put some work into before going to the next step.

4. Stats. With all the major things in place, we can go into the numbers. Tweaking HP, AC, DC and damage output/reach is the easiest part. I strongly advice using the guidelines from DMG. They are not perfect, but they are not meant to be perfect. They work well for me as guidelines. From what I read, I have a feeling that we are looking at 3-5 encounters of a harder variety (enemy is prepared and fighting on his ground).

5. Polishing. Introduce the details that connect with things past and future. Maybe get some ideas from PC backgrounds, or foreshadow the enemies to come. Look at the rarely use abilities/spells and make a sweet spot to use them to make your PC feel good.


My take
Entonces, this is a Duergar post serving the evil wizard and guarding the entrance. The guard is not on the high alert, but take heir duties seriously and use all means at their disposal, magic and mundane to stop any wannabe intruders from getting past them, laying their lives for it, if need be.

What are their resources - they have a good position with a single entrance and defensive positions, they are well equipped and trained and have limited access to wizard spells.

The front gate is not guarded - this is not a good position to be, all in the open and vulnerable. The active guard shift is in Area 1. There are three guard shifts, switching every 8 hours. The second shift is available as reinforcements on the short notice. The third guard shift and the leadership of the post only interfere if the situation gets serious and it takes time for them to arrive.

The defense plan is as follows:
There are guards visually watching the entrance to the barricade (I will call the spiked walls barricades) for the duration of the watch. However, every guard shift also has a low-level magic user that sets the mental -Alarm- to the entrance area (conveniently 20 feet wide). In case any of the alarms go off, all the guards on the shift go invisible and watch the situation develop.

They will not attack right away. The barricades at the entrance can only be opened from inside and first, the attackers have to get over them. Climbing the 10 feet spiked wall demands an Athletics+Dex DC 12 check and causes some minor damage on a failure.
The purpose of the first wall is, however, not to stop the intruders, but to make them split up. As soon as Duergars see part of intruders over the wall, they attack. They also send one of them to warn the rest of the gauntlet about the fight. Unless the PCs manage to take the guard shift on duty by surprise, the rest of the enemies will be ready.

The areas above and bellow (on the map) the first wall are unreachable even for enlarged Duergar in the center, so, if I were them I would trap them. Invisible caltrops are nice, but I would add the good ol' pit trap for the good measure so that the enemy is forced to fight in the area between the two walls. The walls should have peepholes/arrow slits there so that the guards are not forced to enlarge to be able to fight. Also enlarging is very limited in time, so enemy falling back and waiting out the effect is a danger that the guards are aware of.

If they fail to kill/capture whoever gets over the 1st wall before his companions join the fight (insert the party-appropriate checks to open/break the entrance), the Duergar will switch to fighting defensively, waiting for reinforcements to arrive. The arriving shift will -Message- the defenders to assess the situation before turning invisible and joining the fight. Depending on the situation, they either enter and directly assault with all they have, or the remnants of the defenders fake the flight and retreat to Area 2, luring the attackers into the Ambush by reinforcements.

Here is where caltrops come handy - the guards know the safe route (check to notice the way by PCs) while their pursuers might take some damage and get slowed in the killing ground. In case the intruders do not follow, the spellcaster(s) will cast -Flaming Sphere- to damage those in Area 1 and make them decide - In or Out? After some time Commander of the gauntlet will arrive with the 3rd shift of guards in the final attempt to stop the intruders.

We are looking at 4 encounters.

1. Traps at the entrance.

2. Guard Shift.

3. Reinforcements.

4. Last Ditch Effort.

The encounters overlap unless PCs manage to overcome them on time. It is quite possible for the heroes to have to withdraw in the face of all the defenders coming together if they do not assault quickly. Not sure how the possibility of "losing" to NPCs sits with your players, but that is how I DM. In my experience foreshadowing that if the guarded gauntlet is not taken quickly, the Duergars are known to be able to withstand a very strong assault, helps a lot.

The NPCs. I would probably make it as simple as I can - the invis/enlarge and spellcasting is already enough things to keep track of.

For NPCs, I'd go with 3-4 CR1 Guards on each shift, a CR2 Conjurer, and a CR3 leader. Having more than one non-mook NPC per wave is important, else he gets focused and nuked before playing his part in the encounter.

For Guards I'd go with the MM Duergar, improving the armor to Chain Mail, giving them halberds and an equivalent of Polearm Master Feat - OOA when leaving or entering reach. Stop movement on a hit.

For Conjurers I'd say level 3-4 spellcaster with 3-4 extra HD is good enough. Cantrips: Blade Ward, Message, Shocking Grasp; Level 1 - Shield, Grease, Thunderwave, Level 2 - Flaming Sphere, Web. Focus on surviving more than anything else, especially with the first shift one. He hopes to hold on until reinforcements, not to become a hero.

For Shift Leaders and I'd go for diversity, but you can keep it simple. Some ideas are a Priest (as per MM template) his spells are appropriate for the encounter, even Sanctuary. And Spirit Guardians can foreshadow the creatures of the Portal; a Warlock of Asmodey with Repelling blast to push PCs into those spiky walls and some debuffs or a Sergeant, modeled close to the Hobgoblin Captain (Leadership).

Commander of the Gauntlet can be as tough as CR5. If you feel that this encounter warrants a magic item reward, he could be the one using it against the PCs. You can make him just a tough Veteran or a gish-type spellcater. He can also be the one who goes HUGE and swings for 3x damage dice.

I hope this gives you some ideas,

Best of Luck

 

[Ancalagon]

[MENTION=6899046]Dan Chernozub[/MENTION]

Thank you for a thoughtful response. I'll provide more info:

1: The gate opens every 27 years. The Duergar's leaders have been warned of possible intruders/invaders, and have fortified the area. The gate cannot be closed for 28 days. Stairs lead to the gate, and because of this it's hard to shoot inside from outside.

2: There isn't a lot of areas the Duergars can't reach because of their polearms. By my reconning, it should be 20 feet. However, there are a few dead corners and placing at the least a few caltrops in there would help

3: I see what you mean about letting one or two go over the wall, but the Duergars are hoping to scare potential intruders away with seemingly giants attacking from a well defended position. Where the PCs not so keen on getting inside, they probably would not press. There isn't a lot of foreshadowing per se, but the mere sight of the spiked walls should be a huge red flag that something is up.

4: You may have noted two very thin tunnels? These are escape areas for the Duegars, they can shrink to small size (the tunnel is 1 feet across), if the fight is truly lost they can go there.

5: The "exit" tunnel is trapped. The Duergars may "encourage" the PCs to flee that way and fall into the traps (pit traps). Beyond the area is a "semi-wild" zone with more traps and semi-static monsters. The Duergars know how to traverse it safely, the PCs do not. Their goal will be to provide word to the Duergar leadership (a runner will be dispatched immediately), hope that the PCs die in the "semi wild", and the Duergar leadership will then prepare a new defensive position deeper in the dungeon.

 

[Ancalagon]

I think if i remember it right 2e had aoo but only if you moved out of the reach of a mob. I might be wrong eventually, but i am 100% sure even the early goldbox games had that mechanic and they were partially 1e.

On your Problem: If they hit hard make them squishy. 10hp is nothing in 5e. 30hp is something.
Do not give them polearm mastery which would allow these AOO.
Balance it for your specific Party.

Dwarfes in my Point of view have high hitpoints and medium to high armor, so if you want them to be Feeling like dwarves you might think about lowering their damage Output. It will be hard enough for casters in your Party to maintain concentration.

How does the Party fight? Do they go all out dpr or do they buff / debuff /evaluate a Scenario and seek for tactical advvantages / have any means to Scout ahead invisible etc. That all has to be taken into account. A single wizard familliar capable of hiding or turning invisible or going undetected ( a rat e.g.) might Change the whole Thing.

Charm spells can create havoc. Area effect spells can trivialise things. What Level is the Party?

Come over with more Detail info pls if you want real advice.

Well I *did* mention the level of the party in my original post you know as well as the class.

The party's access to area of effect spells isn't fantastic (no fireballs) but they do have some.

First, as mentioned they have access to a Tiny Servant with a dragon breath spell on (3d6 cone), which will go off once or twice before the Duergars smash it. They have access to moonfire via the paladin, and the cleric has spirit guardians. Perhaps the most dangerous for the Duergar will be the warlock's fear spell. However, Duergars *do* have advantage to saves vs spells so they will hard to affect.

They may send the warlock invisible ahead to check things out, but the caltrops will severely hinder that.

 

[Dan Chernozub]

[MENTION=6899046]Dan Chernozub[/MENTION]

Thank you for a thoughtful response. I'll provide more info:

1: The gate opens every 27 years. The Duergar's leaders have been warned of possible intruders/invaders, and have fortified the area. The gate cannot be closed for 28 days. Stairs lead to the gate, and because of this it's hard to shoot inside from outside.

2: There isn't a lot of areas the Duergars can't reach because of their polearms. By my reconning, it should be 20 feet. However, there are a few dead corners and placing at the least a few caltrops in there would help

3: I see what you mean about letting one or two go over the wall, but the Duergars are hoping to scare potential intruders away with seemingly giants attacking from a well defended position. Where the PCs not so keen on getting inside, they probably would not press. There isn't a lot of foreshadowing per se, but the mere sight of the spiked walls should be a huge red flag that something is up.

4: You may have noted two very thin tunnels? These are escape areas for the Duegars, they can shrink to small size (the tunnel is 1 feet across), if the fight is truly lost they can go there.

5: The "exit" tunnel is trapped. The Duergars may "encourage" the PCs to flee that way and fall into the traps (pit traps). Beyond the area is a "semi-wild" zone with more traps and semi-static monsters. The Duergars know how to traverse it safely, the PCs do not. Their goal will be to provide word to the Duergar leadership (a runner will be dispatched immediately), hope that the PCs die in the "semi wild", and the Duergar leadership will then prepare a new defensive position deeper in the dungeon.

Thanks for the clarification.

IIRC per vanila 5e rules Duergar could not shrink in size. I don't like the idea that their plan is to scary off the invaders. They must be pretty sure that whoever is coming should be pretty determined. Or is there another, potentialy easier-looking way in?

However, I think most of my points still stand.

A few new thoughts:
Barricades from A0 to A1 are never opened?
How do Duergar get inside the "fortress in the mid A1?
Can the Duergar fight using walls w/o size change?

PS I don't get the trapped exit tunel part, either. It seems like the only direction PCs will go, so if the Duergar want them there, they might as well let them through.