D&D 5E (2014) Design Debate: 13th-level PCs vs. 6- to 8-Encounter Adventuring Day

[MostlyDm]

The benefit of the random summoning system is "chaos", if you like chaos and a living world that is unpredictable even to the DM. I do, because I'm a simulationist more than a narrativist--systems interest me more than stories. If you like narrative pacing and plots, I recommend deciding in advance whether the demon is going to succeed on its roll, and what reinforcements it summons, so you can factor that into your story's plot.

Well said.

I think one can appreciate such things without caring more about systems than stories, though. I like for my games to *feel* simulationist, at any rate... even though the single most interesting thing to me is the unpredictable emergent story that the party creates.

I don't think narrative pacing is necessarily at odds with a simulationist style, either... But you need a broad acceptable range of narrative. If one hates anticlimax, unpredictable protagonist death, or similar then I think you're 100% correct.

But look at the very popular Song of Ice and Fire series. Lots of anticlimax, unexpected and unsatisfying deaths... There's a fascinating emergent story, there, and it has pacing. But it's not a traditional pace.

 

[Celtavian]

[MENTION=5834]Celtavian[/MENTION] I fully understand finding useful tactics, I find that to be a fun aspect of my game. But I am not on a search for the perfect collection of proven tactics, which is what it sounds like your group is doing. Don't they find it boring to constantly be playing the same tactics every encounter? Sure, I suppose in one campaign the devilsight warlock could be player by Mike instead of Tim, but that only changes things up so much. As a group, it sounds like at some point you guys will have a set party composition and then no one will ever deviate from that composition for any reason.

One of them seems bored. He's making house rules to make the game far more deadly and he's a player that never DMs. Not everyone wants to go along with that. They all do realize that the game is very limited as far as powerful choices. They want more books and feel 5E is releasing material at too slow a pace. That is likely because they're used to Pathfinder. Not sure how long we'll stick with 5E. I don't want to go back to the complexity of Pathfinder, but something with more choices would be nice. The advantage/disadvantage mechanic seemed cool at first, but it is used for so many abilities and rules that there is no way to go once you have advantage or disadvantage. Everything else just becomes pointless, even Inspiration. Something just feels lacking in 5E at the moment.

 

[hawkeyefan]

One of them seems bored. He's making house rules to make the game far more deadly and he's a player that never DMs. Not everyone wants to go along with that. They all do realize that the game is very limited as far as powerful choices. They want more books and feel 5E is releasing material at too slow a pace. That is likely because they're used to Pathfinder. Not sure how long we'll stick with 5E. I don't want to go back to the complexity of Pathfinder, but something with more choices would be nice. The advantage/disadvantage mechanic seemed cool at first, but it is used for so many abilities and rules that there is no way to go once you have advantage or disadvantage. Everything else just becomes pointless, even Inspiration. Something just feels lacking in 5E at the moment.

Gotcha.

Could you position maybe scaling back the power gaming as an alternative? Instead of making house rules to make the game more deadly, maybe come up with race and class selections that are not picked with optimization in mind? That will result in the same thing. I don't know if your players would dig that....but maybe you position it as a challenge. "Okay....for this upcoming Underdark campaign, you guys are all going to play human soldiers that have been captured by the drow....can you survive?" That kind of thing. This means they'd all be humans, and also leans heavily toward martial classes, although perhaps a war cleric or something like that would be possible.

Maybe they'd be into that as an exercise or a challenge. Maybe try something like that in a one off adventure before committing to an entire campaign.

Alternatively, you could institute some rules to curb the min-maxing. Again, this may not be liked by your group, from teh sound of things, but it might be worth talking about with them. Make the training options more prominent. Okay, you're going to multi-class? How does that happen? How does your 3rd level fighter start to become a warlock?

My playing group has tried so many different approaches in order to keep the game fresh. This is across all editions, though. We haven't played enough 5E yet to be bored with it. Often times, the DM will create the PCs ahead of time, and then assign or have people pick randomly. A lot of players balk at this, initially, but usually it winds up creating an experience that was different than they were used to, and so it worked out being a positive.

Another time, I had them all make characters, and then when we got to the table, I said okay, pass your character sheet to the player to the left, and then they played the characters that were passed.

All this is to say that there may be alternative options to creating a rewarding play experience for your group. Yes, you can alter mechanics to make monsters tougher or the game more deadly. You can play with environmental factors and other in game aspects to help achieve the level of challenge that you're looking for. But you can also change up the way you play the game, or some of the aspects of character creation and so on.

I say this as a DM who would personally dread going back to Pathfinder.

I liked that system well enough....and I would gladly play it if anyone in my group wanted to run some stuff....but I don't think I will ever DM it again. I found the experience so frustrating that I'd exhaust all other options before going back.

 

[Celtavian]

Gotcha.

Could you position maybe scaling back the power gaming as an alternative? Instead of making house rules to make the game more deadly, maybe come up with race and class selections that are not picked with optimization in mind? That will result in the same thing. I don't know if your players would dig that....but maybe you position it as a challenge. "Okay....for this upcoming Underdark campaign, you guys are all going to play human soldiers that have been captured by the drow....can you survive?" That kind of thing. This means they'd all be humans, and also leans heavily toward martial classes, although perhaps a war cleric or something like that would be possible.

Maybe they'd be into that as an exercise or a challenge. Maybe try something like that in a one off adventure before committing to an entire campaign.

Alternatively, you could institute some rules to curb the min-maxing. Again, this may not be liked by your group, from teh sound of things, but it might be worth talking about with them. Make the training options more prominent. Okay, you're going to multi-class? How does that happen? How does your 3rd level fighter start to become a warlock?

My playing group has tried so many different approaches in order to keep the game fresh. This is across all editions, though. We haven't played enough 5E yet to be bored with it. Often times, the DM will create the PCs ahead of time, and then assign or have people pick randomly. A lot of players balk at this, initially, but usually it winds up creating an experience that was different than they were used to, and so it worked out being a positive.

Another time, I had them all make characters, and then when we got to the table, I said okay, pass your character sheet to the player to the left, and then they played the characters that were passed.

All this is to say that there may be alternative options to creating a rewarding play experience for your group. Yes, you can alter mechanics to make monsters tougher or the game more deadly. You can play with environmental factors and other in game aspects to help achieve the level of challenge that you're looking for. But you can also change up the way you play the game, or some of the aspects of character creation and so on.

I say this as a DM who would personally dread going back to Pathfinder.

I liked that system well enough....and I would gladly play it if anyone in my group wanted to run some stuff....but I don't think I will ever DM it again. I found the experience so frustrating that I'd exhaust all other options before going back.

I can't do Pathfinder any more either. The thought of prepping a Pathfinder gives me a nightmares. 5E is much more enjoyable to work with as a DM as far as creating adventures.

One of the problems is also that we're old now. We're all in our 40s and have been playing for 30 years plus. At this point they all seem focused on feeling powerful in a fantasy world rather than role-playing and story. They want to do as much damage and be as powerful as possible focusing mostly on combat encounters. When it comes to roleplaying and story, they want to gloss it over or let someone else handle it. The group seems jaded at this point. Maybe it's time to quit playing D&D. They're too set in their ways when it comes to D&D.

We were having more fun playing FFG's Star Wars game. The new game system where they didn't know how to power game seemed to spark their interest in role-playing and story again. When they don't know what they're doing mechanically, they seem to enjoy the game more and focus less on power gaming. I think 3E/Pathfinder really created this power gaming mentality in my group after playing it for over a decade that has carried over to 5E. That's why I think a new game system might be the answer to refocusing on role-playing and story.

 

[matskralc]

Two fifth level spells and a 4th level spell. The party is six members. They have 6 fifth level spells and 9 4th level spells.

I love puzzles!

The cleric 10 and sorcerer 10 have four 5th level slots and six 4th level slots between them. Those two are easy. Unless there's a hidden multiclass here that I missed. So we gotta find two more 5ths and three more 4ths.

The paladin 2/bladesinger 8 has one 5th and three 4th (9th level caster for purposes of determining spell slots), but can't actually learn any 5th level spells. We found all our 4ths, but we're still missing a 5th.

The ranger/eldritch knight doesn't have any 5th, 4th, or even 3rd. At best, he's ranger 7/EK 3 (4th level caster), giving him four 1st and three 2nd. This PC has a feat and a 20 Dex, so must be a variant human with 2 ASIs? Meaning ranger 6/EK 4 (still a 4th level caster) is his best caster potential, and that's the same deal, four 1st and three 2nd. I'm not sure why a ranger 6 would bother taking more than 3 levels in EK, though, especially since this ranger archetype has proficiency in Wis saves waiting for it at level 7.

The warlock/paladin/sorcerer can't have any 5th. At best, he has two 4th, and that's if he's a warlock 1/paladin 1/sorcerer 8 (8th level caster) or warlock 8/paladin 1/sorcerer 1 (1st level caster plus 8th level pact magic). But he can't have any 4th, since the cleric, sorcerer and bladesinger have already accounted for all nine 4th level slots. Probably warlock 1/paladin 6/sorcerer 3 (6th level caster plus 1st level pact magic)? No other division would make any sense. Plus, this means he's one of the paladins with an aura. But he's got 3rd level slots at best.

The paladin/warlock can have two 5th if he's warlock 9/paladin 1 (just 9th level pact magic), or two 4th if he's warlock 8/paladin 2 (2nd level caster plus 8th level pact magic). He can't have two 5th, because then the party has seven 5th and he has to be at least a paladin 6 in order to have the party's other aura. He can't have any 4th because we've already accounted for all those. He's probably warlock 2/paladin 8 (8th level caster plus 2nd level pact magic) with access to 2nd level slots.

So I'm stumped. Either you accidentally ascribed an extra fifth level slot to the group somewhere, or somebody optimized himself into a 5th level slot he shouldn't have. Or maybe I'm not as good an optimizer as I thought!

Anyway, we know the cleric couldn't be casting banishments since he's concentrating on bless. The bladesinger can't be casting banishments since he's casting booming blades or Attacking. So that leaves the sorcerer as the only other character with access to 4th-level spells. He can get off a 5th level banishment in order to get two demons off the battlefield. But at some point, the sorcerer cast haste (it can't be the other sorcerer, since that one can't learn 3rd level spells yet and is busy concentrating on hex, anyway). If he did that first, then he's too busy concentrating on that to cast banishment (and dropping that haste takes the bladesinger and sharpshooter out for a round). But if he didn't cast haste on his first turn but instead waited until after he did some banishing, that's a pretty inefficient use of the spell. At any rate, once he gets one banishment off, he's done, since he can't cast anymore without ending the first one(s).

But...there were two 5th level banishments and a 4th level banishment used. Well, I guess ignoring/forgetting about the concentration mechanic is one way to optimize your PC! Probably not one that I'd allow at my table, though. Even weirder is that the demons don't seem to have been paying much attention to the caster who's disappearing their allies left and right? For somebody with an 18 Int, this marilith isn't very bright.

So anyway, at best, your spell save DCs are likely going to be 17 (8 + 4 prof bonus + 5 ability modifier). We don't know who was getting banished, but the marilith fails her save 9% of the time, the vrocks 49% of the time, the hezrou 57% of the time, and the chasme 64% of the time. There were five demons targeted, and four failed. Assuming the worst save (the chasme) was always the target, there's a 41% chance of getting at least 4 of them to fail. Not bad, but probably not the best EV play.

What's also weird is that between six PCs and six chasmes, not a single PC failed a single DC 12 Con save at the start of their turn, despite the fact that, since these things can fly, each PC should probably have had to make one or two, if not five or six. Four hezrous and six PCs, not a single failed DC 14 Con save. Four flying vrocks and six PCs, not a single failed DC 14 Con save. Although, to be fair, the sorcerer-that-can-concentrate-on-multiple-spells probably banished them, I guess.

With a +5 Con and proficiency in Con saves (which it's impossible for every PC to have at this point), they still fail a DC 12 Con save 10% of the time and fail a DC 14 Con save 20% of the time (EDIT: Oh wait! I forgot about the auras on those saves. Well, they don't stack, but I still find it unlikely that all 6 PCs stayed clumped together. Those are really bad tactics). Round 1 should have involved every single vrock emptying his Stunning Screech barrel, every hezrou getting up in as many PCs' faces (or within 10 feet) as they can, and every chasme should have parked itself over top of as many PCs as possible and started droning. The marilith, instead of doing something stupid like getting surrounded by melee fighters while the archer snipes her, sees that big juicy sorcerer sitting over there and wants him. She's got 14 troops on hand: they surround and grapple as many PCs as possible and she enjoys targeting the squishy caster with her 7 attacks per round. Oh, some of the PCs got away? I'm going to teleport over there. DM's call whether the sorcerer she's grappling with her tail comes with her!

 

[MostlyDm]

I can't do Pathfinder any more either. The thought of prepping a Pathfinder gives me a nightmares. 5E is much more enjoyable to work with as a DM as far as creating adventures.

One of the problems is also that we're old now. We're all in our 40s and have been playing for 30 years plus. At this point they all seem focused on feeling powerful in a fantasy world rather than role-playing and story. They want to do as much damage and be as powerful as possible focusing mostly on combat encounters. When it comes to roleplaying and story, they want to gloss it over or let someone else handle it. The group seems jaded at this point. Maybe it's time to quit playing D&D. They're too set in their ways when it comes to D&D.

We were having more fun playing FFG's Star Wars game. The new game system where they didn't know how to power game seemed to spark their interest in role-playing and story again. When they don't know what they're doing mechanically, they seem to enjoy the game more and focus less on power gaming. I think 3E/Pathfinder really created this power gaming mentality in my group after playing it for over a decade that has carried over to 5E. That's why I think a new game system might be the answer to refocusing on role-playing and story.

Sounds like a rough situation, man.

Hawkeyefan had some good suggestions, I think, but they might not be extreme enough to shake your group out of their current mindset.

You could really change it up, play Savage Worlds or FATE or something completely counter to the 3.5/PF style. Or play something like CoC or Dark Heresy to really break away from the "feeling like powerful heroes" vibe, heh.

I've had players that optimized mechanics of their characters, and I certainly did it myself in 3.5, but never in the way your table does. It was always optimized to a more specific goal, like... I want to make the most effective Con 5 dagger-wielding rogue that I possibly can, or whatever.

The optimization started at the midway point in character creation, after all the big decisions had been made. 100% optimization is different, more difficult, certainly.

But honestly your players' attitudes seem like the biggest problem. Fighting over a beholder's anti-magic? That seems way off base to me.

Good luck, man. Hope you guys find a setting/system that shakes them out of their rut and keeps you all having fun.

 

[MostlyDm]

Matskralc, one thing: Celtavian already mentioned that he was not running Banishment correctly earlier in the thread, when Hemlock asked about it. So your breakdown doesn't really prove much... Yeah, he ran banishment wrong. Yeah, it made the encounter dramatically easier. It happens. He knows better for next time.

 

[Lord Twig]

Can't reply to this all. Too much going on today, but a couple things jumped out.

No. She was leading the band and had been crushing humanoids. She decided to move forward to attack with her troops.

If the players won't do it, the NPC don't have to do it either. This was poor tactics by a master tactician.

Two fifth level spells and a 4th level spell. The party is six members. They have 6 fifth level spells and 9 4th level spells. Three spells eliminated four targets fairly quickly thinning the group. They still had 4 5th level spells and 8 4th level spells.

You already admitted a mistake here. Happens to the best of us.

Still, those are some high level spells getting tossed out. Basically they went nova because they had no fear that they would need those spells later. As a DM your job is to make them worry.

She had six Shadow Demon scouts out. The party spotted them. They ran. The party moved back in the other direction, hid, and ambushed the shadow demons using pass without trace. It's very hard to ambush groups with players with high Wisdom, the Observation feat, and double proficiency bonus on their Perception. Have all of those things in the group, it's extremely hard to ambush them. Most of the group is drow and one Devilsight player with 120 foot darkvision. So they can match what the opponent can see. Even invisibility is not a guarantee of success against them. If they hear something, they will cast see invisibility and annihilate it.

This is something I find strange as well. Do you not play with characters that build to notice things? Every single party I've played with has had double proficiency bonus Stealthy scouts and double proficiency bonus Perception. Every one of them. If I want them to not notice something, I have to make it up. Which I've started doing on occasion. This adventure is about testing demons out of the book to see how they do. I'll start modifying them after I get a feel for them.

And now we get to the heart of the problem. You basically just give the party the win here. It's great that they notice things, but you are telling me that they can see an incorporeal (completely silent) creature of darkness, in darkness (basically invisible), before they themselves can be spotted? How fast are they moving to be able to stealth all day long (in full plate no less) so well that they can't be spotted by incorporeal shadow creatures (in complete darkness) while they can see the shadow demons.

Okay, sure. Let's go ahead and give them that (I wouldn't, but whatever).

There are 6 shadow demons. Are they all grouped together? Why? How about putting them in a grid so they are all 120' apart? Each one can see two others. Only one shadow demon needs to get away to warn the Marilith. It is so trivially easy to allow a lone shadow demon to get away.

The one that got away destroys the parties advantage completely. They have no idea that there is anything more than shadow demons out there. They have no idea that they missed one.

Once they are alerted the demons just need to wait at a bend in the tunnel that puts the party less than a full move away. Or wait till they are crossing a chasm, or a bridge, or going up a cliff, or anything other than a flat featureless plane.

Because he was running by them provoking AoOs from them and does substantial damage with his whip. If someone was hitting you for a bunch of damage, might you not try to attack him? The bladesinger is a paladin2 /bladesinger 8. So he has a lot of smites and Booming Blade is surprisingly effective with a whip. That was an interesting tactic to see given I didn't think much of Booming Blade or the Bladesinger class. My eyes have been opened.

They closed on them after the marilith was dead. They did some damage. At that point it was, meh damage in my opinion. Chasme don't have great hit rolls so a few shield spells.

Again, they can cast "a few shield spells because they have no fear that they will need them again for the rest of the day.

The master tactical genius went forward with her demons in front of her looking to do some damage. They were providing her with cover as she closed. She figured she could leave with her teleport. So I'll give you an exact sequence.

The cleric cast bless on the paladin/warlock, paladin/bladesinger, and ranger/fighter (Notice lots of multiclassing and paladins...we might have to try a campaign without multiclassing). So the opening round the archer beats the Marilith on initiative and the cleric beats the sharpshooter (due to the Alertness feat, he has a high initiative modifier).

So the Sharpshooter with his magic bow (+2 bow) and bless fires all attacks at the marilith. He moves forward 30 feet to hunter's mark. We are using Unearthed Arcana material. So he has Close Quarters Combat and Archery Style (fighter/ranger) and is a Deep Stalekr ranger (1 extra attack on the first round of combat). He Action Surges and unloads five Sharpshooter arrows at her. Attack bonus +4 prof +5 dex +2 bow +1 Close quarters fighting +2 archery style -5 sharpshooter +1d4 bless. Each attack is +9 +1d4. He hits four of five attacks. He does 1d8+1d6+17 per attack. So he did 100 or so in round one of her 180 points. As you know cover and distance don't much matter to a Sharpshooter.

She was pretty much neutered in the opening round. 80 hit points against a six man party is absolutely nothing and will disappear quite quickly. I could have had her run and leave. That was the only way she was going to survive. I figured she would want to try to and hammer a character, so she advanced teleporting to the archer. And she did some damage to him and he had to use a shield spell. He's a ranger/fighter Eldritch Knight. But by round two she took hits from the warlock/paladin/sorcerer using eldritch blast[/.I] with hex. The bladesinger smote her a couple of times with his whip. I think the archer hammered her with two attacks only hitting with one that round. She was down to 10 hit points by round 3 or some trivial amount. I figured she knew she was heading back to the Abyss and decided to go out swinging.

Using a couple spell slots in one round, again, because why not? Not going to need them again today!

The fight was the second fight of the day. The first one was the six shadow demon scouts they ambushed. That didn't use up much resources. They are traveling right now. So they only get a few encounters a day. Soon they'll be walking into Baphomet's maze. I've taken some measures to limit resource recovery, so they have to preserve more than they've been doing. Though they still aren't using much in terms of resources due.

Let me see if I can remember. In that deadly fight, they used:
2 5th level banishes
1 4th level banish
1 1st level bless
1 3rd level haste with 3 sorcery points to twin it (cast on bladesinger and sharpshooter)
1 1st level hunter's mark (I think this dropped after he was attacked by the marilth)
1 1st level hex warlock slot

I don't think they cast much else. Just absorbed the hit points, fell back down the tunnel to a relatively safe location, and took a short rest to recover some hit points at a safe location after defeating the warband.

Putting aside the fact that they should never have been allowed to ambush the shadow demons, you forgot to include all the shield spells cast and the ones sacrificed for smites.

But you know what? Ultimately you want your players to have fun. If they like flat featureless planes for combat and always getting the drop on their enemies, then changing the enemies to add abilities is what you are going to have to do.

Allow the Marilith to parry ranged attacks. Give her the teleport as bonus action. Double her hit points. Give her (and a bunch of other demons) the ability to cast Cloud Kill (they are all immune to poison). Maybe some wall spells to shape the battle field.

If that is what you and your players like to do, go ahead!

Oh, one more thing. You keep claiming that your players are awesome and there is no stopping them. This implies that everyone else is not-so-awesome and that their tactics are inferior. That is why people keep popping up to tell you you are wrong. Because there definitely are ways of stopping them, you just don't want to use them (like breaking a bow).

Instead maybe just say that you like to let your players be the toughest things around and let them beat on creatures far above there level. That seems to be what they like, and if they are having fun, then that's the most important thing. You will even get suggestions on ways to let them keep beating on things.

 

[hawkeyefan]

I can't do Pathfinder any more either. The thought of prepping a Pathfinder gives me a nightmares. 5E is much more enjoyable to work with as a DM as far as creating adventures.

One of the problems is also that we're old now. We're all in our 40s and have been playing for 30 years plus. At this point they all seem focused on feeling powerful in a fantasy world rather than role-playing and story. They want to do as much damage and be as powerful as possible focusing mostly on combat encounters. When it comes to roleplaying and story, they want to gloss it over or let someone else handle it. The group seems jaded at this point. Maybe it's time to quit playing D&D. They're too set in their ways when it comes to D&D.

We were having more fun playing FFG's Star Wars game. The new game system where they didn't know how to power game seemed to spark their interest in role-playing and story again. When they don't know what they're doing mechanically, they seem to enjoy the game more and focus less on power gaming. I think 3E/Pathfinder really created this power gaming mentality in my group after playing it for over a decade that has carried over to 5E. That's why I think a new game system might be the answer to refocusing on role-playing and story.

It's funny because my group sounds very similar....we're all upper 30s early 40s and have been playing for decades, across every edition. I think our power gaming tendencies began in 2e and then spiked in 3e, and then Pathfinder was the edition that finally showed the inherent problems with that play style for many of our players. We started to scale things back and try different approaches to the game.

I think 5e has worked out because it shifted the focus a little back the other way, and that's the way our group was leaning. Sounds like your guys were still leaning toward the power gaming and trying to master the game to full effectiveness.

It may be that you have to try another system. It could just be that the idea of D&D (in any flavor, even Pathfinder) just puts them into power gamer mode. You guys should talk about this and discuss options. You can probably come up with some ideas that might help alleviate things a bit.

 

[Celtavian]

I love puzzles!

The cleric 10 and sorcerer 10 have four 5th level slots and six 4th level slots between them. Those two are easy. Unless there's a hidden multiclass here that I missed. So we gotta find two more 5ths and three more 4ths.

The paladin 2/bladesinger 8 has one 5th and three 4th (9th level caster for purposes of determining spell slots), but can't actually learn any 5th level spells. We found all our 4ths, but we're still missing a 5th.

So calculate 1 less 5th.Did it make a big difference? No? Didn't think it did.

Anyway, we know the cleric couldn't be casting banishments since he's concentrating on bless. The bladesinger can't be casting banishments since he's casting booming blades or Attacking. So that leaves the sorcerer as the only other character with access to 4th-level spells. He can get off a 5th level banishment in order to get two demons off the battlefield. But at some point, the sorcerer cast haste (it can't be the other sorcerer, since that one can't learn 3rd level spells yet and is busy concentrating on hex, anyway). If he did that first, then he's too busy concentrating on that to cast banishment (and dropping that haste takes the bladesinger and sharpshooter out for a round). But if he didn't cast haste on his first turn but instead waited until after he did some banishing, that's a pretty inefficient use of the spell. At any rate, once he gets one banishment off, he's done, since he can't cast anymore without ending the first one(s).

The cleric can cast banishment. After the marilith is dead, bless isn't needed. This is the part many don't seem to be getting. You don't need bless up the whole combat. Just to deal with the tough character. Two rounds of bless was all it took. We have three paladins. They can all cast bless. That is four of six characters capable of casting bless.

But this discussion is irrelevant. We have a house rule that allows two concentration spells active at one time as long as one is a buff cast on another player.

But...there were two 5th level banishments and a 4th level banishment used. Well, I guess ignoring/forgetting about the concentration mechanic is one way to optimize your PC! Probably not one that I'd allow at my table, though. Even weirder is that the demons don't seem to have been paying much attention to the caster who's disappearing their allies left and right? For somebody with an 18 Int, this marilith isn't very bright.

The marilith was dead when the banishments were cast. Stop trying to look for holes in a long, complex combat that I was not going to take the time to explain every round. All you need to know is the marilith was dead early in round 3. That's all you need to know. It was done with a bless, a magic bow, and Sharpshooter very, very quickly.

What's also weird is that between six PCs and six chasmes, not a single PC failed a single DC 12 Con save at the start of their turn, despite the fact that, since these things can fly, each PC should probably have had to make one or two, if not five or six. Four hezrous and six PCs, not a single failed DC 14 Con save. Four flying vrocks and six PCs, not a single failed DC 14 Con save. Although, to be fair, the sorcerer-that-can-concentrate-on-multiple-spells probably banished them, I guess.

With a +5 Con and proficiency in Con saves (which it's impossible for every PC to have at this point), they still fail a DC 12 Con save 10% of the time and fail a DC 14 Con save 20% of the time (EDIT: Oh wait! I forgot about the auras on those saves. Well, they don't stack, but I still find it unlikely that all 6 PCs stayed clumped together. Those are really bad tactics). Round 1 should have involved every single vrock emptying his Stunning Screech barrel, every hezrou getting up in as many PCs' faces (or within 10 feet) as they can, and every chasme should have parked itself over top of as many PCs as possible and started droning. The marilith, instead of doing something stupid like getting surrounded by melee fighters while the archer snipes her, sees that big juicy sorcerer sitting over there and wants him. She's got 14 troops on hand: they surround and grapple as many PCs as possible and she enjoys targeting the squishy caster with her 7 attacks per round. Oh, some of the PCs got away? I'm going to teleport over there. DM's call whether the sorcerer she's grappling with her tail comes with her!

They were stacked together. There are two paladins. One that melees, one that is ranged. All have good Con and Wisdom saves except for the Sorcerer (no wisdom). Cleric is Wisdom focused. Who cares if they miss a save after the mariilth is dead. It doesn't matter at that point. Only the marilith was a formidable challenge for the PCs as a group. The other creatures were nuisances. A few did miss saves here and there to hezrou stench and I think one did to vrock stun screech. Not enough that it mattered. Not sure why you think it would matter unless a substantial number missed it at once, which would require some really unlucky rolling.

Paladins can cast bless.

I think it's not much of a puzzle. DC 12 and 14 saves are not hard to make with paladin auras. Once you save against the chasme, their power does nothing.

I didn't keep a round by round battle log. The whole point of the discussion is that one Sharpshooter Ranger/Eldritch Knight with a +2 bow took 100 hit points from a 189 point mariilth in a single round. By round two the other PCs knocked her down to 10 or 20 points. By round three she was dead. This is without the entire party focus firing her. Just two or three characters. She did very little damage to them. The rest of the combat is irrelevant. The other demons did some damage here and there, but certainly not enough to matter or change the tide of combat. It became a tedious exercise in rolling once the marilith was down.