So my idea is a gigantic (150 ft. long?) demonic centipede that shoots flaming oil from it's mouth (fireballs essentially but they leave a burning area behind) and it creates shockwaves and stuff. Also, you have to destroy it from its tail to its head 10 foot chunk by ten foot chunk because otherwise its plating is so thick its practically invulnerable and the tail end is the only part that isn't fully covered. Every time you deal enough damage to the end chunk, it ruptures and falls off, cracking the plating on the next chunk and allowing you to damage it. I wan't it to be a challenge for level 9-10 party of four as a climatic fight to save a town from this evil demonic creation. The only problem is I have no idea how to make, balance, or run this kind of thing, and some advice would be very much appreciated. Thank you!
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DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
Well... the largest issue I see is balancing against the lethality of the thing. What you're describing sounds like a pretty high-end monster, at least from a size perspective, as most creatures that size have health and damage that would pretty easily clap a party of level 9-10 players. A Purple Worm is a good comparison for something of a similar size, and it's CR 15. A centipede of that size should have a ton of hp, Strength and Con out the wazoo, and a swallow ability, for sure. Couple that with the fire breath, and I don't see a way to make a traditional battle not a three-turn TPK.
That said, nothing says this has to be a traditional battle. I'd collaborate with your players on this one. I assume they know they're going to have this showdown. Have them spend a session or two preparing with the townsfolk for the creature's arrival. They can set traps, they can establish healing waystations, they can build barricades and choke points. They might train a militia to distract the creature or a fire brigade to counter its fire breath. While doing this, you start building out your combat session around the decisions they make. On game day, give your players a map of the town, set up with a series of "nodes" that represent the various preparations they've built. They lead the creature from node to node, triggering traps, engaging with firefighters who eliminate the fire breath, swinging by the local church for some quick heals, etc. Each time they stop at a node, they have to destroy a segment of the monster before they can move on.
As for the monster itself, I'd look at something like a Purple Worm as a starting point. Probably cut waaaay down on the damage and the sting. Probably could add something like a Young Red Dragon-equivalent fire breath (it looks like a lethal amount of damage, but if the players have time to prepare, they should be able to find a way to counter it). If you want it to stick to things, you could drop the base damage and then say if they fail a save, they catch fire and must spend an action to douse themselves or take additional fire damage every turn.
I think the issue will be the size. At 150’ long, that would be 15 10’ increments. Will you allow damage to spill over? If you say each chuck takes 50 hp to destroy, and the party does 52, does the extra 2 roll into the next chuck or just kind of vanish?
If you don’t let it roll over, you are probably looking at the party destroying 1-2 chunks per round, which would means a 7-10 round fight. That would be pretty epic, but it would take a long time, and once fights go longer than 5 rounds, things usually start going badly for the party (and can get a little frustrating for the players irl, though destroying chunks will help show progress so that might not be as bad) after 10 rounds, lots of spells would stop (all the duration 1 minute ones) and then things are going to be really rough.
So I’d say maybe treat it like a math problem. Figure out your party’s average damage per round, and use that to set the thing’s hit points so the fight will last however long you want it to last.
I’d also make that fireball thing a recharge power. And you’ll want to give it some legendary resistance, otherwise hold monster ends the fight in the first round. And some legendary actions to break up the character’s turns. I’d probably give it a burrow speed, without the tunnel building trait, and tremor sense as that can really be fun (for the DM) since the thing will have total cover while underground, but it could still rise up from underneath to attack.
I’d also think about it trying to flee. If it gets knocked down to only 1-3 segments, it would probably want to run.
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
To follow up on a point earlier: the most interesting part of a boss fight is generally figuring things out; once you understand its move set, the rest of the fight can easily turn into a slog. As such, I recommend designing epic fights to have phases (like video game bosses), where each phase lasts no more than 2-3 rounds before you mix things up. For example, you could have additional effects trigger when five segments have been destroyed, and again when ten segments have been destroyed (at ten segments destroyed, I might cause it to metamorphose into something else -- say, a giant moth-demon -- and leave the entire segment destruction shtick behind).
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
Segmented: Grolka is composed of 14 body segments and a head segment. Each body segment has AC 17 and 15 Hit Points. Only the rear body segment can be damaged at a time, because all the other segments are so heavily plated that they are immune to all damage. If a segment is dealt enough damage that it is destroyed and excess damage remains, that damage carries over to the next segment. Once eleven of the body segments are destroyed, unless the amount of damage that destroyed the eleventh body segment carries over and destroys the remaining three segments, Grolka covers herself in a cocoon and undergoes a metamorphosis (See Ascendance below). Grolka’s Head has AC 22, 100 Hp, and resistance to damage from Nonmagical Bludgeoning, Piercing, and Slashing damage. If Grolka’s head is destroyed, she dies.
Massive: Grolka can be climbed onto with a successful DC 15 Strength (Athletics) or Dexterity (Acrobatics) check. Grappled creatures do not cost her extra movement.
Ascendance: When Grolka becomes cocooned (see segmented above), she becomes immune to all damage for three rounds. On initiative count 0 of the third round, she bursts from her cocoon as Grolka, Abhorrent Tyrant at full health.
Inevitable (3/day): Whenever Grolka fails on a saving throw, she can choose to succeed instead. When she does, she sacrifices her rear segment, which is destroyed.
Actions
Multiattack: Grolka makes two mandibles attacks and can use blazing shot, if available.
Mandibles: Melee weapon attack, + 9 to hit, reach 10 ft., one target. Hit: 21 (3d10+5) piercing damage, plus 5 (1d10) poison damage, and the target must make a DC 17 dexterity saving throw or be grappled (Escape DC 17). Grolka can have only one creature grappled at a time and can’t make mandible attacks against other targets.
Swallow: Grolka targets one creature she is grappling. That creature must succeed on a DC 17 dexterity saving throw or be swallowed, and no longer grappled. A swallowed creature is blinded and restrained, and has total cover against attacks and effects originating from outside of Grolka. At the beginning of each of Grolka’s turns, swallowed creatures must make a DC 17 Constitution saving throw, taking 11 (2d10) fire damage on a failed save, or half as much on a successful one a flaming oil roils around in Grolka’s stomach. If Grolka takes 25 or more damage in one turn from a creature she has swallowed, Grolka must make a DC 16 Constitution saving throw or regurgitate all swallowed creatures. When Grolka dies, a creature can exit her corpse by spending 5 feet of movement, exiting prone. When Grolka is coccooned (see Ascendance above), all swallowed creatures are ejected from her and are propelled to a space within 30 feet of Grolka, chosen by the DM. Grolka can have up to two swallowed creatures at a time.
Flaming shot (recharge 5-6): Grolka spews flaming oil at a creature of her choice within 90 feet. Ranged weapon attack, range 90 ft., +9 to hit, one target. Hit: 22(4d10) fire damage, and the target is ignited. While ignited, a creature takes 5 (1d10) fire damage at the start of each of their turns. The creature or another creature within reach can use an action to put the fire out. Otherwise, it burns for one minute.
Reactions:
Infernal Glare: When a creature within 30 ft. of Grolka damages her, she can use her reaction to turn her baleful gaze upon that creature. They must make succeed on a DC 16 Wisdom save or be frightened of Grolka until the end of their next turn.
Villain Actions:
Grolka has three Villain actions. She can use them only at the end of another creature’s turn, and only use one per round. Each can only be used once each long rest, and they all recharge at the end of a long rest. They have a recommended order of use but you can use them in whatever order you please.
Witness My Power! Grolka rears up and roars in a terrifying and impressive display. Each creature within 60 feet of Grolka must make a DC 16 Wisdom saving throw. On a failure, a creature is frightened of Grolka for one minute (Save end at end of turn). On a success, a creature suffers no ill effects.
Ground Pound: Grolka rears up and slams into the ground powerfully, creating a concussive shockwave. Each creature within 30 feet of Grolka must make a DC 17 Constitution saving throw as the sonic wave roils over them. On a failed save, a creature takes 22(4d10) thunder damage, is knocked prone, and is deafened for one minute (save end at end of turn). On a success, a creature takes half as much damage only.
Flames of the Abyss: Grolka rears up and sprays bursts of flaming oil from her mouth. Choose three points within 90 feet of Grolka. Each creature within ten feet of those areas must make a DC 17 Dexterity saving throw, taking 22 ( 4d10) fire damage on a failed save or half as much on a successful one. Those areas then burn for the next minute. A creature that enters a burning area for the first time on a turn or starts their turn there takes 11 (2d10) fire damage. A burning area can be extinguished by pouring 30 gallons of water on it in one round.
Rollback Post to RevisionRollBack
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
Hello,
So my idea is a gigantic (150 ft. long?) demonic centipede that shoots flaming oil from it's mouth (fireballs essentially but they leave a burning area behind) and it creates shockwaves and stuff. Also, you have to destroy it from its tail to its head 10 foot chunk by ten foot chunk because otherwise its plating is so thick its practically invulnerable and the tail end is the only part that isn't fully covered. Every time you deal enough damage to the end chunk, it ruptures and falls off, cracking the plating on the next chunk and allowing you to damage it. I wan't it to be a challenge for level 9-10 party of four as a climatic fight to save a town from this evil demonic creation. The only problem is I have no idea how to make, balance, or run this kind of thing, and some advice would be very much appreciated. Thank you!
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
"When are we gonna take a snack break?"
Well... the largest issue I see is balancing against the lethality of the thing. What you're describing sounds like a pretty high-end monster, at least from a size perspective, as most creatures that size have health and damage that would pretty easily clap a party of level 9-10 players. A Purple Worm is a good comparison for something of a similar size, and it's CR 15. A centipede of that size should have a ton of hp, Strength and Con out the wazoo, and a swallow ability, for sure. Couple that with the fire breath, and I don't see a way to make a traditional battle not a three-turn TPK.
That said, nothing says this has to be a traditional battle. I'd collaborate with your players on this one. I assume they know they're going to have this showdown. Have them spend a session or two preparing with the townsfolk for the creature's arrival. They can set traps, they can establish healing waystations, they can build barricades and choke points. They might train a militia to distract the creature or a fire brigade to counter its fire breath. While doing this, you start building out your combat session around the decisions they make. On game day, give your players a map of the town, set up with a series of "nodes" that represent the various preparations they've built. They lead the creature from node to node, triggering traps, engaging with firefighters who eliminate the fire breath, swinging by the local church for some quick heals, etc. Each time they stop at a node, they have to destroy a segment of the monster before they can move on.
As for the monster itself, I'd look at something like a Purple Worm as a starting point. Probably cut waaaay down on the damage and the sting. Probably could add something like a Young Red Dragon-equivalent fire breath (it looks like a lethal amount of damage, but if the players have time to prepare, they should be able to find a way to counter it). If you want it to stick to things, you could drop the base damage and then say if they fail a save, they catch fire and must spend an action to douse themselves or take additional fire damage every turn.
I think the issue will be the size. At 150’ long, that would be 15 10’ increments. Will you allow damage to spill over? If you say each chuck takes 50 hp to destroy, and the party does 52, does the extra 2 roll into the next chuck or just kind of vanish?
If you don’t let it roll over, you are probably looking at the party destroying 1-2 chunks per round, which would means a 7-10 round fight. That would be pretty epic, but it would take a long time, and once fights go longer than 5 rounds, things usually start going badly for the party (and can get a little frustrating for the players irl, though destroying chunks will help show progress so that might not be as bad) after 10 rounds, lots of spells would stop (all the duration 1 minute ones) and then things are going to be really rough.
So I’d say maybe treat it like a math problem. Figure out your party’s average damage per round, and use that to set the thing’s hit points so the fight will last however long you want it to last.
I’d also make that fireball thing a recharge power. And you’ll want to give it some legendary resistance, otherwise hold monster ends the fight in the first round. And some legendary actions to break up the character’s turns. I’d probably give it a burrow speed, without the tunnel building trait, and tremor sense as that can really be fun (for the DM) since the thing will have total cover while underground, but it could still rise up from underneath to attack.
I’d also think about it trying to flee. If it gets knocked down to only 1-3 segments, it would probably want to run.
Thanks, these suggestions are good
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
"When are we gonna take a snack break?"
To follow up on a point earlier: the most interesting part of a boss fight is generally figuring things out; once you understand its move set, the rest of the fight can easily turn into a slog. As such, I recommend designing epic fights to have phases (like video game bosses), where each phase lasts no more than 2-3 rounds before you mix things up. For example, you could have additional effects trigger when five segments have been destroyed, and again when ten segments have been destroyed (at ten segments destroyed, I might cause it to metamorphose into something else -- say, a giant moth-demon -- and leave the entire segment destruction shtick behind).
"Sooner or later, your Players are going to smash your railroad into a sandbox."
-Vedexent
"real life is a super high CR."
-OboeLauren
"............anybody got any potatoes? We could drop a potato in each hole an' see which ones get viciously mauled by horrible monsters?"
-Ilyara Thundertale
Megapede？
Did you make this? Or did you find this online or from some game or something? @Wysperra
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
"When are we gonna take a snack break?"
I made this on docs, just want to run it through you guys, haven't made it's second form yet, but any comments?
Grolka, The Undefied
Gargantuan Fiend (Demon), Chaotic Evil
AC Depends, see below
HP Depends, see below
Speed 60 ft., Burrow 60 ft., Climb 60 ft.
STR DEX CON INT WIS CHA
20 10 20 16 16 8
Skills: Perception +6
Saves: Con +8, Wis +4
Damage Resistances: Necrotic
Damage Immunities: Fire, Poison
Condition Immunities: Prone, Frightened
Senses: Darkvision 120 ft., Tremorsense 30 ft., Passive Perception 16
Challenge Rating 10
Segmented: Grolka is composed of 14 body segments and a head segment. Each body segment has AC 17 and 15 Hit Points. Only the rear body segment can be damaged at a time, because all the other segments are so heavily plated that they are immune to all damage. If a segment is dealt enough damage that it is destroyed and excess damage remains, that damage carries over to the next segment. Once eleven of the body segments are destroyed, unless the amount of damage that destroyed the eleventh body segment carries over and destroys the remaining three segments, Grolka covers herself in a cocoon and undergoes a metamorphosis (See Ascendance below). Grolka’s Head has AC 22, 100 Hp, and resistance to damage from Nonmagical Bludgeoning, Piercing, and Slashing damage. If Grolka’s head is destroyed, she dies.
Massive: Grolka can be climbed onto with a successful DC 15 Strength (Athletics) or Dexterity (Acrobatics) check. Grappled creatures do not cost her extra movement.
Ascendance: When Grolka becomes cocooned (see segmented above), she becomes immune to all damage for three rounds. On initiative count 0 of the third round, she bursts from her cocoon as Grolka, Abhorrent Tyrant at full health.
Inevitable (3/day): Whenever Grolka fails on a saving throw, she can choose to succeed instead. When she does, she sacrifices her rear segment, which is destroyed.
Actions
Multiattack: Grolka makes two mandibles attacks and can use blazing shot, if available.
Mandibles: Melee weapon attack, + 9 to hit, reach 10 ft., one target. Hit: 21 (3d10+5) piercing damage, plus 5 (1d10) poison damage, and the target must make a DC 17 dexterity saving throw or be grappled (Escape DC 17). Grolka can have only one creature grappled at a time and can’t make mandible attacks against other targets.
Swallow: Grolka targets one creature she is grappling. That creature must succeed on a DC 17 dexterity saving throw or be swallowed, and no longer grappled. A swallowed creature is blinded and restrained, and has total cover against attacks and effects originating from outside of Grolka. At the beginning of each of Grolka’s turns, swallowed creatures must make a DC 17 Constitution saving throw, taking 11 (2d10) fire damage on a failed save, or half as much on a successful one a flaming oil roils around in Grolka’s stomach. If Grolka takes 25 or more damage in one turn from a creature she has swallowed, Grolka must make a DC 16 Constitution saving throw or regurgitate all swallowed creatures. When Grolka dies, a creature can exit her corpse by spending 5 feet of movement, exiting prone. When Grolka is coccooned (see Ascendance above), all swallowed creatures are ejected from her and are propelled to a space within 30 feet of Grolka, chosen by the DM. Grolka can have up to two swallowed creatures at a time.
Flaming shot (recharge 5-6): Grolka spews flaming oil at a creature of her choice within 90 feet. Ranged weapon attack, range 90 ft., +9 to hit, one target. Hit: 22(4d10) fire damage, and the target is ignited. While ignited, a creature takes 5 (1d10) fire damage at the start of each of their turns. The creature or another creature within reach can use an action to put the fire out. Otherwise, it burns for one minute.
Reactions:
Infernal Glare: When a creature within 30 ft. of Grolka damages her, she can use her reaction to turn her baleful gaze upon that creature. They must make succeed on a DC 16 Wisdom save or be frightened of Grolka until the end of their next turn.
Villain Actions:
Grolka has three Villain actions. She can use them only at the end of another creature’s turn, and only use one per round. Each can only be used once each long rest, and they all recharge at the end of a long rest. They have a recommended order of use but you can use them in whatever order you please.
DM: He doesn't have much besides the skin on his bones. Me: I'll take the skin on his bones, then.
Down, down, down the road, down the Witches Road
"You see a gigantic, monstrous praying mantis burst from out of the ground. It sprays a stream of acid from it's mouth at one soldier, dissolving him instantly, then it turns and chomps another soldier in half with it's- "
"When are we gonna take a snack break?"
Pinterest is your friend.
"Sooner or later, your Players are going to smash your railroad into a sandbox."
-Vedexent
"real life is a super high CR."
-OboeLauren
"............anybody got any potatoes? We could drop a potato in each hole an' see which ones get viciously mauled by horrible monsters?"
-Ilyara Thundertale