Hi fellow dungeon masters. this is my first post here so sorry if i am not posting in the correct place
my party is level 7, and the BBEG of my campaign is a Lich. i have idea for content to get them to level 14 but i am unsure if that will be to defeat a Lich. i prefer not lowering the power of the lich because i want the final encounter to be epic.
Once your players hit level 10/11, you will see a dramatic jump in their abilities. Depending on how many players you have and whether you give them magic items, they might actually wipe the floor with a lich by the time they hit level 14 - especially if the lich is fighting alone.
You will get a better sense for your party's strength as they keep leveling up, and especially once they crest tier 3 play at level 11. My advice is to keep the level 14 plan and make adjustments to the final battle as they are getting close to it. It's perfectly reasonable that a bunch of level 14s can take on a lich.
In general, solo monsters are a lot easier to fight than monsters with minions, lair effects, environmental hazards and battlefield puzzles - this is because the party simply has a numbers advantage. They will be hitting your baddie more often than you can hit them. Sure, a lich might be able to cast Power Word Kill, but that's pretty much their whole turn, and they can only do that once. Meanwhile, the fighter can attack 3 times, the cleric can invoke divine intervention and heal, the wizard can counterspell and polymorph, the sorcerer can rain down lightning or fire, and the rogue is probably averaging 30-40 damage each turn. This is why legendary actions and resistances are so important; they keep boss monsters in the game longer.
TL;DR - level 14s versus a lich is fine, and wait until they're closer to it to think about how you'll design the final fight.
I just tested a party of four level 14 characters in the Encounter Builder vs. a Lich (CR 21). A fight vs. a single Lich for that party is a Deadly encounter. Further, it's on the edge between Deadly and a CR of 19 wouldn't be Deadly so this should be all set for your goal of an epic final fight.
You can quite easily adjust difficulty through resource control. Typically parties enter boss fights after having already used lots of their daily resources/abilities and might have to fight a bunch of minions before encountering, so they might not get a SR either.
So if at that point you realize that the Lich is probably too strong, you can decrease the difficulty by allowing them to face the Lich with more resources remaining.
It's quite remarkable how strong a party of level 14 is at full resources. They will have access to 7th level spells. But if you feel the need, one more level will get the casters 8th level spells. That's a major power boost.
Also, if you need to tackle a specific boss mechanic to reduce the difficulty, you could make them complete a Q that gives them a much needed protective or offensive tool.
And finally. Environmental and tactical elements. The lich doesn't have a lot of HP. Level 14 players can deal a lot of damage. Their weapons are magical too. So the Lich may actually go down quite quickly, if the Lich is an idiot. So it needs to be smart. But if it is smart, then it has some devastating abilities that will wreck the party. Find this balance. 😄
A party of level 14 can defeat a single lich in probably less than 10 rounds due to it's low AC and HP, despite being CR 21 with powerful spells and Lair Actions, giving a short but intense clash your party can survive.
There are two pretty straighforward ways to tip the scales of the fight in my opinion.
Reduce the Lich by a spell level. having it capped at 8th level does a ton of damage to the threat of the Lich.
Give the party a quest to ward against a specific kill condition the lich might have. This will not reduce the entire impact of the lich's arsenal, but gives the party some method of sustain in the event you feel they wont have the capability.
When i've flirted with the idea of using a Lich, i've tended to make it more about finding the phylactery, and telling the story of the mage becoming the lich as they encounter him, becoming more lich-like with every resurrection. The bonus of this is you can gauge how strong the party is at the points leading up to it, and if you need to give them an extra quest/boost along the way it becomes much easier to scale into that last fight that might push the limits but ultimately lead to their triumph that they are looking for.
How does a Lich only have 135 HP as a CR21? It's going to get smoked in round 1 against level 14 PCs unless it has some way to control the battlefield and avoid ever being hit.
A single level 14 PC built for Nova damage can easily do more than 135 damage in a turn. The lich may have a bunch of powerful spells but you're going to need to get really creative to find some way to keep it alive to use them
A party of four, if rested, can pretty reliably beat a foe with a CR of twice the party's level; if you want a lich to be a challenge for a level 14 party you'll have to give it minions, a situational advantage, or have a way to make sure the PCs are drained of resources before they reach the lich.
How does a Lich only have 135 HP as a CR21? It's going to get smoked in round 1 against level 14 PCs unless it has some way to control the battlefield and avoid ever being hit.
A single level 14 PC built for Nova damage can easily do more than 135 damage in a turn. The lich may have a bunch of powerful spells but you're going to need to get really creative to find some way to keep it alive to use them
I think the HP is low because the point is to fight it more than once. The crux of this monster is its phylactery, so just because you smoke it today doesn't mean you've actually taken care of the threat.
That said, I find that a lot of high CR monsters need their HP maxed out or doubled to survive long enough to make the fight satisfying. Mages in particular. Also, CR usually is something I laugh at as I tinker with the stat block. It's mostly okay at low levels, but then again you have things like will-o'-wisps and hell hounds that will absolutely wreck your tier 2 party with just a couple on the map.
I think the HP is low because the point is to fight it more than once. The crux of this monster is its phylactery, so just because you smoke it today doesn't mean you've actually taken care of the threat.
That could be true but I doubt it. Beating the Lich once gives you the same XP as beating any other CR 21 monster even though it's a cakewalk in comparison. I'm pretty sure it's meant to be catagorized as CR 21 to fight and beat it once, regardless of whether it ever comes back
That said, I find that a lot of high CR monsters need their HP maxed out or doubled to survive long enough to make the fight satisfying. Mages in particular.
Yeah I'm pretty sure it is 100% this. Challenge Rating is well known to be pretty terrible, but it especially bad for any monsters that cast spells.
Looking at the DM Guide table for creating monsters, a Lich has the HP of a CR 5 monster, and AC of CR 10. It also doesn't even have Offensive capabilities of anything near a CR 21, which should be doing ~150 damage per round. Nothing about it makes any sense for it to be CR 21, it is just artificially jacked up because it can cast spells.
I think the lich is getting a lot of distorted CR math because of miscellaneous immunities, but you can make it come closer to its CR by changing its spell list to something not terrible.
It is not really possible for us to say how tough the combat, I don't think there will be any problems with a party of level 14 fighting a Lich the difficulty is deciding what minions to give it to make it a tough fight. See how they cope with combats as ther progress to determine what is needed for an epic battle. Lich's are glass cannon's so that can be a little tricky.
Lets look at a Paladin with a pretty standard +2 longsword at level 14 if they score a crit against a lich they do 16d8 + strength damage (not including any extra damage from the magic sword) when they plug in the 4th level smite. On average that will be around 80 if their other attack hits (very likely with +12 to hit vs a 17AC) they could take it ut on their own in a single round. Of course if the Lich wins initiative and dominates the paladin that attack could take down one of the party.
Combat difficulty depends a huge amount on :
The number of PCs in the party and whether they have any NPC allies
How optimized the players build are
How smart the players play their characters (inclding how much the PCs know about lich fighting strategy and whether they are able to cause surpise)
How smart you play the Lich
What magic item the party have
Luck
In general as players go up in levels encounter difficulty becoumes a bit of a joke. Deadly encounters are generally pretty easy I think this is because the assumptions are of virtually no magic items and 8 encounters per day. As an example let me describe the last session in my current compaign (as a player) at level 10 in a party of 5. I wouldn't say the PCs are particularly highly optimised (we are all single class) but we do have some quite powerful magic items.
We were infiltrating the residence of an evil sorcerer which we had been to before at a much lower level (2 or 3 when we were essentially being forced to do his will), and we had knowledge of his teleportation circle, we knew the teleportation circle which a frienly NPC would cast for us so we were able to prepare outselves beforehand for example my druid cast summon draconic spirit).
2 Iron Golems guarded the telportation circle, at CR16 one Iron golem is supposed to be a deadly encounter, we used some resources but we were holding back unsure of how powerful the sorcerer was, the DM didn't play the Golems particularly smartly and the combat was pretty straight forward.
Out the teleportation room (we didn't need or have time for a short rest) the corridors were to small for my draconic spirit we found two more iron golems one in a fixed position down a side corridor and the other patrolling a corridor that crossed our route a pass, a without trace and a well timed run accross the corridor got us past them and to the entrace to the sorcerers lab. Pass without trace meant were were able to surprise the sorcerer (who had 4 guard drakes) and failing hold person meant the battle was more like an execution (the drakes do tiny damage so we could ignore them). I've no idea how powerful the sorcerer was because he never got to act.
To get out of the place there was no option but to fight the othe two golems we times our exit so the golems were a long way apart the the second golem only entered combat in the 2nd round.
Overall we had three combats which would be classed as deadly encounters without a short rest. The DM was expecting it to be tough do doable for us with a mixture of strategy and luck we found it pretty easy (My druid only used one of their 5th level spell slots and none of their 4th (they did use all their 3rd level slots though one of those was to cast dispel magic on a trap), the other PCs also had plenty of resources left (we were nt sure if there would be anything else we would need to deal with).
That said, I find that a lot of high CR monsters need their HP maxed out or doubled to survive long enough to make the fight satisfying. Mages in particular.
Yeah I'm pretty sure it is 100% this. Challenge Rating is well known to be pretty terrible, but it especially bad for any monsters that cast spells.
Looking at the DM Guide table for creating monsters, a Lich has the HP of a CR 5 monster, and AC of CR 10. It also doesn't even have Offensive capabilities of anything near a CR 21, which should be doing ~150 damage per round. Nothing about it makes any sense for it to be CR 21, it is just artificially jacked up because it can cast spells.
Agreed, and the spells aren't even that exciting when you think about them.
Scrying, Detect Magic, Detect Thoughts and Animate Dead are useless once combat has already started. Power Word Stun is kind of...polite?...for an evil creature, and not worth wasting an 8th level slot on when you could just upcast a damage spell. Dominate Monster eats too much of the lich's action economy to be worthwhile. PWK only works if your target is worn down already. Dimension Door and Plane Shift are for when the DM doesn't want the BBEG annihilated. So ignoring upcasting, that leaves us with a bunch of low level damage spells, one use of Finger of Death, and one use of Disintegrate. The only actual threatening spells it can use reliably are Cloudkill and Fireball.
Agreed, and the spells aren't even that exciting when you think about them.
Scrying, Detect Magic, Detect Thoughts and Animate Dead are useless once combat has already started. Power Word Stun is kind of...polite?...for an evil creature, and not worth wasting an 8th level slot on when you could just upcast a damage spell. Dominate Monster eats too much of the lich's action economy to be worthwhile. PWK only works if your target is worn down already. Dimension Door and Plane Shift are for when the DM doesn't want the BBEG annihilated. So ignoring upcasting, that leaves us with a bunch of low level damage spells, one use of Finger of Death, and one use of Disintegrate. The only actual threatening spells it can use reliably are Cloudkill and Fireball.
This creature is so not a CR 21.
While I agree in princlple,I thiink you are overplaying it a bit
Animate dead means that if the Lich has had a week or so to replenish their supply of undead minions from the local commoners the party could be facing 60 odd of them, (though that shouldn't be included in the CR), spread them out enough for AOE to not be very efficient and the party will be facing an annoying horde of skellie Archers.
Against level 14 characters Wizards and Sorcerers are likely to be under 100HP and possibly even d8 classes so PWK an unhurt wizard is a valid option.
Dominate Monster is not very clear on the difference between "a simple and general course of action" and "precise control". While "Attack that creature" may mean a single attack I would class "Kill that Creature" to be a valid command which would mean it would continue attacking until the creature was dead. I would also say "kill that creature as quickly as possible" is simple and general enough to be valid and then the dominated creature would be pumping all the resources it could into the attack. The phrase "course of action" implies to me that it can span across multiple rounds and is more tha just "an action". It certainly isn't worth the Lich taking precise control with their action every round how effective it is using simple and general courses of action is DM dependent.
As well as the offensive spells you mention, I could see globe of invulnerability, counterspell and dispel magic being used defensively.
Note this rule from the section on spellcasting NPCs:
Spell Swaps. One way to customize an NPC spellcaster is to replace one or more of its spells. You can substitute any spell on the NPC’s spell list with a different spell of the same level from the same spell list. Swapping spells in this manner doesn’t alter an NPC’s challenge rating
This is fairly obviously false, some spell mixes are vastly more dangerous than others, but I think the CR for spellcasting monsters is based on some theoretical measure of the power of higher level spell slots. For example, consider this layout for higher level spells:
7th: forcecage, symbol (long duration spell... assume it's already been cast somewhere on a prior day)
Note this rule from the section on spellcasting NPCs:
Spell Swaps. One way to customize an NPC spellcaster is to replace one or more of its spells. You can substitute any spell on the NPC’s spell list with a different spell of the same level from the same spell list. Swapping spells in this manner doesn’t alter an NPC’s challenge rating
This is fairly obviously false, some spell mixes are vastly more dangerous than others, but I think the CR for spellcasting monsters is based on some theoretical measure of the power of higher level spell slots. For example, consider this layout for higher level spells:
7th: forcecage, symbol (long duration spell... assume it's already been cast somewhere on a prior day)
That would be not at all a good thing to walk in on.
You can give a lich extra spells as well
"Magic Collectors. Liches collect spells and magic items. In addition to its spell repertoire, a lich has ready access to potions, scrolls, libraries of spellbooks, one or more wands, and perhaps a staff or two. It has no qualms about putting these treasures to use whenever its lair comes under attack."
Note this rule from the section on spellcasting NPCs:
Spell Swaps. One way to customize an NPC spellcaster is to replace one or more of its spells. You can substitute any spell on the NPC’s spell list with a different spell of the same level from the same spell list. Swapping spells in this manner doesn’t alter an NPC’s challenge rating
This is fairly obviously false, some spell mixes are vastly more dangerous than others, but I think the CR for spellcasting monsters is based on some theoretical measure of the power of higher level spell slots. For example, consider this layout for higher level spells:
7th: forcecage, symbol (long duration spell... assume it's already been cast somewhere on a prior day)
That would be not at all a good thing to walk in on.
With a spell caster like a lich I recommend figuring out what it's actually going to do and base difficulty assessment off that.
Even within the existing lich spell list a toxic fog lich that hides in a cloudkill and tries to pick off the weakest targets with spells finger of death is a very different encounter to the fire mage lich that keeps their distance and spams fireball.
I also think the final boss is worth the effort of customizing for a unique strategy and calibrating to what you want.
Agreed, and the spells aren't even that exciting when you think about them.
Scrying, Detect Magic, Detect Thoughts and Animate Dead are useless once combat has already started. Power Word Stun is kind of...polite?...for an evil creature, and not worth wasting an 8th level slot on when you could just upcast a damage spell. Dominate Monster eats too much of the lich's action economy to be worthwhile. PWK only works if your target is worn down already. Dimension Door and Plane Shift are for when the DM doesn't want the BBEG annihilated. So ignoring upcasting, that leaves us with a bunch of low level damage spells, one use of Finger of Death, and one use of Disintegrate. The only actual threatening spells it can use reliably are Cloudkill and Fireball.
This creature is so not a CR 21.
While I agree in princlple,I thiink you are overplaying it a bit
Animate dead means that if the Lich has had a week or so to replenish their supply of undead minions from the local commoners the party could be facing 60 odd of them, (though that shouldn't be included in the CR), spread them out enough for AOE to not be very efficient and the party will be facing an annoying horde of skellie Archers.
Forcing the party to wait as you roll attacks for 60 CR 1/4 creatures in a boss battle is a good way to get dice thrown at you. It's not a good way to actually accomplish anything in the battle, they've only got +4 to hit for 1d6+2 damage, so it's likely that you're going to need to roll a nat 20 to hit most of the party.
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Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
We need to remember Legendary actions too. And the dc is pretty heavy (18).
Paralyzing touch or frightening gaze as Legendary Actions. Or 6d6 AoE dmg.
20 spell save DC is also insane.
So it is definitely a strong foe, but it needs to be smart. For example, DC 20 Disintegrate or finger of death is brutal. Followed by a bit of paralysis and frighten.
It effectively has 22 AC with Shield. Mirror Image helps too.
You can change the scale of the battle, the spell list, and the lich's HP if you are the DM if it's a homebrew world (i assumed it was with the presentation of the question).
I'd probably make them encounter him first in a mage tower he once resided in, filled with traps and an initial encounter with him (reports report seeing a lich near a mage tower). You can present lore, create traps that reduce the party's means, and bring forth a weakened version of the lich outside of his new place of residence.
Battle two can be less involved directly with the lich but showcase a battle of intellect between the party's highest INT/WIS based player and him. I might have a chess board on the floor and characters get slotted into roles on the chess board minus the wizard, along with some other people, and have rigged the game to not be so much chess but movement based decision making to best slot the party members and other npc's along for the ride in product roles to win the battle to defeat the opposing King piece.
If lich loses he's still intrigued by the party and invites them to come to the center of his lair (top if you want it to be there) and you fight him with lair effects that add mobs that are enhanced by the lair itself (which gives you an excuse to raise their CR, the DC of the saving throws, the +hit, the hp, whatever you want). Zombies too weak? well in this Lair maybe they get +40 health, and their fear spell has a 15-18 range save requirement and their hits are a bit heavier because it buffs them, so they can stand between the frontline melee combatants and the lich and cause those folks problems. Backline not threatened? replace legendary actions with triggered events at set % of Hp left on the Lich that brings a few other mobs into battle. thats the beauty of DND to me, all of the books are suggestions and advice on what to do, they don't end all be all you unless you are adamant about not deviating (which some are, and thats perfectly fine too imo).
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Hi fellow dungeon masters. this is my first post here so sorry if i am not posting in the correct place
my party is level 7, and the BBEG of my campaign is a Lich. i have idea for content to get them to level 14 but i am unsure if that will be to defeat a Lich. i prefer not lowering the power of the lich because i want the final encounter to be epic.
any ideas or suggestion? Thanks
Once your players hit level 10/11, you will see a dramatic jump in their abilities. Depending on how many players you have and whether you give them magic items, they might actually wipe the floor with a lich by the time they hit level 14 - especially if the lich is fighting alone.
You will get a better sense for your party's strength as they keep leveling up, and especially once they crest tier 3 play at level 11. My advice is to keep the level 14 plan and make adjustments to the final battle as they are getting close to it. It's perfectly reasonable that a bunch of level 14s can take on a lich.
In general, solo monsters are a lot easier to fight than monsters with minions, lair effects, environmental hazards and battlefield puzzles - this is because the party simply has a numbers advantage. They will be hitting your baddie more often than you can hit them. Sure, a lich might be able to cast Power Word Kill, but that's pretty much their whole turn, and they can only do that once. Meanwhile, the fighter can attack 3 times, the cleric can invoke divine intervention and heal, the wizard can counterspell and polymorph, the sorcerer can rain down lightning or fire, and the rogue is probably averaging 30-40 damage each turn. This is why legendary actions and resistances are so important; they keep boss monsters in the game longer.
TL;DR - level 14s versus a lich is fine, and wait until they're closer to it to think about how you'll design the final fight.
I just tested a party of four level 14 characters in the Encounter Builder vs. a Lich (CR 21). A fight vs. a single Lich for that party is a Deadly encounter. Further, it's on the edge between Deadly and a CR of 19 wouldn't be Deadly so this should be all set for your goal of an epic final fight.
You can quite easily adjust difficulty through resource control. Typically parties enter boss fights after having already used lots of their daily resources/abilities and might have to fight a bunch of minions before encountering, so they might not get a SR either.
So if at that point you realize that the Lich is probably too strong, you can decrease the difficulty by allowing them to face the Lich with more resources remaining.
It's quite remarkable how strong a party of level 14 is at full resources. They will have access to 7th level spells. But if you feel the need, one more level will get the casters 8th level spells. That's a major power boost.
Also, if you need to tackle a specific boss mechanic to reduce the difficulty, you could make them complete a Q that gives them a much needed protective or offensive tool.
And finally. Environmental and tactical elements. The lich doesn't have a lot of HP. Level 14 players can deal a lot of damage. Their weapons are magical too. So the Lich may actually go down quite quickly, if the Lich is an idiot. So it needs to be smart. But if it is smart, then it has some devastating abilities that will wreck the party. Find this balance. 😄
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A party of level 14 can defeat a single lich in probably less than 10 rounds due to it's low AC and HP, despite being CR 21 with powerful spells and Lair Actions, giving a short but intense clash your party can survive.
There are two pretty straighforward ways to tip the scales of the fight in my opinion.
Reduce the Lich by a spell level. having it capped at 8th level does a ton of damage to the threat of the Lich.
Give the party a quest to ward against a specific kill condition the lich might have. This will not reduce the entire impact of the lich's arsenal, but gives the party some method of sustain in the event you feel they wont have the capability.
When i've flirted with the idea of using a Lich, i've tended to make it more about finding the phylactery, and telling the story of the mage becoming the lich as they encounter him, becoming more lich-like with every resurrection. The bonus of this is you can gauge how strong the party is at the points leading up to it, and if you need to give them an extra quest/boost along the way it becomes much easier to scale into that last fight that might push the limits but ultimately lead to their triumph that they are looking for.
How does a Lich only have 135 HP as a CR21? It's going to get smoked in round 1 against level 14 PCs unless it has some way to control the battlefield and avoid ever being hit.
A single level 14 PC built for Nova damage can easily do more than 135 damage in a turn. The lich may have a bunch of powerful spells but you're going to need to get really creative to find some way to keep it alive to use them
A party of four, if rested, can pretty reliably beat a foe with a CR of twice the party's level; if you want a lich to be a challenge for a level 14 party you'll have to give it minions, a situational advantage, or have a way to make sure the PCs are drained of resources before they reach the lich.
I think the HP is low because the point is to fight it more than once. The crux of this monster is its phylactery, so just because you smoke it today doesn't mean you've actually taken care of the threat.
That said, I find that a lot of high CR monsters need their HP maxed out or doubled to survive long enough to make the fight satisfying. Mages in particular. Also, CR usually is something I laugh at as I tinker with the stat block. It's mostly okay at low levels, but then again you have things like will-o'-wisps and hell hounds that will absolutely wreck your tier 2 party with just a couple on the map.
That could be true but I doubt it. Beating the Lich once gives you the same XP as beating any other CR 21 monster even though it's a cakewalk in comparison. I'm pretty sure it's meant to be catagorized as CR 21 to fight and beat it once, regardless of whether it ever comes back
Yeah I'm pretty sure it is 100% this. Challenge Rating is well known to be pretty terrible, but it especially bad for any monsters that cast spells.
Looking at the DM Guide table for creating monsters, a Lich has the HP of a CR 5 monster, and AC of CR 10. It also doesn't even have Offensive capabilities of anything near a CR 21, which should be doing ~150 damage per round. Nothing about it makes any sense for it to be CR 21, it is just artificially jacked up because it can cast spells.
I think the lich is getting a lot of distorted CR math because of miscellaneous immunities, but you can make it come closer to its CR by changing its spell list to something not terrible.
It is not really possible for us to say how tough the combat, I don't think there will be any problems with a party of level 14 fighting a Lich the difficulty is deciding what minions to give it to make it a tough fight. See how they cope with combats as ther progress to determine what is needed for an epic battle. Lich's are glass cannon's so that can be a little tricky.
Lets look at a Paladin with a pretty standard +2 longsword at level 14 if they score a crit against a lich they do 16d8 + strength damage (not including any extra damage from the magic sword) when they plug in the 4th level smite. On average that will be around 80 if their other attack hits (very likely with +12 to hit vs a 17AC) they could take it ut on their own in a single round. Of course if the Lich wins initiative and dominates the paladin that attack could take down one of the party.
Combat difficulty depends a huge amount on :
In general as players go up in levels encounter difficulty becoumes a bit of a joke. Deadly encounters are generally pretty easy I think this is because the assumptions are of virtually no magic items and 8 encounters per day. As an example let me describe the last session in my current compaign (as a player) at level 10 in a party of 5. I wouldn't say the PCs are particularly highly optimised (we are all single class) but we do have some quite powerful magic items.
We were infiltrating the residence of an evil sorcerer which we had been to before at a much lower level (2 or 3 when we were essentially being forced to do his will), and we had knowledge of his teleportation circle, we knew the teleportation circle which a frienly NPC would cast for us so we were able to prepare outselves beforehand for example my druid cast summon draconic spirit).
2 Iron Golems guarded the telportation circle, at CR16 one Iron golem is supposed to be a deadly encounter, we used some resources but we were holding back unsure of how powerful the sorcerer was, the DM didn't play the Golems particularly smartly and the combat was pretty straight forward.
Out the teleportation room (we didn't need or have time for a short rest) the corridors were to small for my draconic spirit we found two more iron golems one in a fixed position down a side corridor and the other patrolling a corridor that crossed our route a pass, a without trace and a well timed run accross the corridor got us past them and to the entrace to the sorcerers lab. Pass without trace meant were were able to surprise the sorcerer (who had 4 guard drakes) and failing hold person meant the battle was more like an execution (the drakes do tiny damage so we could ignore them). I've no idea how powerful the sorcerer was because he never got to act.
To get out of the place there was no option but to fight the othe two golems we times our exit so the golems were a long way apart the the second golem only entered combat in the 2nd round.
Overall we had three combats which would be classed as deadly encounters without a short rest. The DM was expecting it to be tough do doable for us with a mixture of strategy and luck we found it pretty easy (My druid only used one of their 5th level spell slots and none of their 4th (they did use all their 3rd level slots though one of those was to cast dispel magic on a trap), the other PCs also had plenty of resources left (we were nt sure if there would be anything else we would need to deal with).
Agreed, and the spells aren't even that exciting when you think about them.
Scrying, Detect Magic, Detect Thoughts and Animate Dead are useless once combat has already started. Power Word Stun is kind of...polite?...for an evil creature, and not worth wasting an 8th level slot on when you could just upcast a damage spell. Dominate Monster eats too much of the lich's action economy to be worthwhile. PWK only works if your target is worn down already. Dimension Door and Plane Shift are for when the DM doesn't want the BBEG annihilated. So ignoring upcasting, that leaves us with a bunch of low level damage spells, one use of Finger of Death, and one use of Disintegrate. The only actual threatening spells it can use reliably are Cloudkill and Fireball.
This creature is so not a CR 21.
While I agree in princlple,I thiink you are overplaying it a bit
Animate dead means that if the Lich has had a week or so to replenish their supply of undead minions from the local commoners the party could be facing 60 odd of them, (though that shouldn't be included in the CR), spread them out enough for AOE to not be very efficient and the party will be facing an annoying horde of skellie Archers.
Against level 14 characters Wizards and Sorcerers are likely to be under 100HP and possibly even d8 classes so PWK an unhurt wizard is a valid option.
Dominate Monster is not very clear on the difference between "a simple and general course of action" and "precise control". While "Attack that creature" may mean a single attack I would class "Kill that Creature" to be a valid command which would mean it would continue attacking until the creature was dead. I would also say "kill that creature as quickly as possible" is simple and general enough to be valid and then the dominated creature would be pumping all the resources it could into the attack. The phrase "course of action" implies to me that it can span across multiple rounds and is more tha just "an action". It certainly isn't worth the Lich taking precise control with their action every round how effective it is using simple and general courses of action is DM dependent.
As well as the offensive spells you mention, I could see globe of invulnerability, counterspell and dispel magic being used defensively.
Note this rule from the section on spellcasting NPCs:
This is fairly obviously false, some spell mixes are vastly more dangerous than others, but I think the CR for spellcasting monsters is based on some theoretical measure of the power of higher level spell slots. For example, consider this layout for higher level spells:
That would be not at all a good thing to walk in on.
You can give a lich extra spells as well
"Magic Collectors. Liches collect spells and magic items. In addition to its spell repertoire, a lich has ready access to potions, scrolls, libraries of spellbooks, one or more wands, and perhaps a staff or two. It has no qualms about putting these treasures to use whenever its lair comes under attack."
With a spell caster like a lich I recommend figuring out what it's actually going to do and base difficulty assessment off that.
Even within the existing lich spell list a toxic fog lich that hides in a cloudkill and tries to pick off the weakest targets with spells finger of death is a very different encounter to the fire mage lich that keeps their distance and spams fireball.
I also think the final boss is worth the effort of customizing for a unique strategy and calibrating to what you want.
Forcing the party to wait as you roll attacks for 60 CR 1/4 creatures in a boss battle is a good way to get dice thrown at you. It's not a good way to actually accomplish anything in the battle, they've only got +4 to hit for 1d6+2 damage, so it's likely that you're going to need to roll a nat 20 to hit most of the party.
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
We need to remember Legendary actions too. And the dc is pretty heavy (18).
Paralyzing touch or frightening gaze as Legendary Actions. Or 6d6 AoE dmg.
20 spell save DC is also insane.
So it is definitely a strong foe, but it needs to be smart. For example, DC 20 Disintegrate or finger of death is brutal. Followed by a bit of paralysis and frighten.
It effectively has 22 AC with Shield. Mirror Image helps too.
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Think some things are overplayed a bit here.
You can change the scale of the battle, the spell list, and the lich's HP if you are the DM if it's a homebrew world (i assumed it was with the presentation of the question).
I'd probably make them encounter him first in a mage tower he once resided in, filled with traps and an initial encounter with him (reports report seeing a lich near a mage tower). You can present lore, create traps that reduce the party's means, and bring forth a weakened version of the lich outside of his new place of residence.
Battle two can be less involved directly with the lich but showcase a battle of intellect between the party's highest INT/WIS based player and him. I might have a chess board on the floor and characters get slotted into roles on the chess board minus the wizard, along with some other people, and have rigged the game to not be so much chess but movement based decision making to best slot the party members and other npc's along for the ride in product roles to win the battle to defeat the opposing King piece.
If lich loses he's still intrigued by the party and invites them to come to the center of his lair (top if you want it to be there) and you fight him with lair effects that add mobs that are enhanced by the lair itself (which gives you an excuse to raise their CR, the DC of the saving throws, the +hit, the hp, whatever you want). Zombies too weak? well in this Lair maybe they get +40 health, and their fear spell has a 15-18 range save requirement and their hits are a bit heavier because it buffs them, so they can stand between the frontline melee combatants and the lich and cause those folks problems. Backline not threatened? replace legendary actions with triggered events at set % of Hp left on the Lich that brings a few other mobs into battle. thats the beauty of DND to me, all of the books are suggestions and advice on what to do, they don't end all be all you unless you are adamant about not deviating (which some are, and thats perfectly fine too imo).