Ways to break a game at lvl20

[HoboKnight]

Hey guys,
Im curius - what ways are there to really break the game at lvl 20? I never played to that level, but I'd like to know and I have never found a comprehensive list.

One thing I know of is Simulacrum spam - simulacrums just self-replicate, meaning at a certain point wizard has at his disposal thousands of casters who can all cast Magic Missile and can do hundreds of thousands of points of damage to a target, no to-hit, no save.

What else?

Thanks

[Unoriginal]

Hey guys,
Im curius - what ways are there to really break the game at lvl 20? I never played to that level, but I'd like to know and I have never found a comprehensive list.

One thing I know of is Simulacrum spam - simulacrums just self-replicate, meaning at a certain point wizard has at his disposal thousands of casters who can all cast Magic Missile and can do hundreds of thousands of points of damage to a target, no to-hit, no save.

What else?

Thanks

You can punch the DM in the face. Or insult them until they lose it.

That's about as nice as breaking a game, but it's quicker.

Alternate answer:

You can only break the game if the DM allows you to.

So just ask them to let you break the game, it's quicker and is less likely to get you kicked out of a group.

[Mastikator]

A wizard who has seen an adult gold dragon can true polymorph into one, wait 1 hour and become one permanently. The gold dragon is CR 17 and can shapeshift into a humanoid of CR 17 or lower, archmage from MM is a humanoid of CR 17 or lower. Thus you can become a creature that can freely switch between wizard 20 and adult gold dragon. Oh and dying just changes you back to your original form.

[Imbalance]

Game is at least partially broken as written. OP exploits can really only damage your own story.

[J-H]

I had a player use Wish to instantly strike the BBEG with Antipathy, no save. The casting time is normally really long. The BBEG was atop a 100'+ temple in the middle of his main city, with most of his army flying and thus having line of sight to him while being busy fighting off several attack groups on the outside of the city, several dozen giants who the party brought in through a teleport ring, and a kraken.

They could save...eventually... but it broke their cohesion for a while and chased off quite a few of the BBEG's minions.

I don't consider that breaking the game.

There is no Pun-Pun equivalent. Simulacrum spam has an endpoint in terms of spell slots available, unless the DM generously rules that Sims start with no spell slots expended.

High end barbarians, especially Zealot barbs, have a very short list of ways to kill them, most of which require specific spells such as Sleep, Calm Emotions, and Power Word: X that are not typically prepared. Otherwise, they can straight up facetank a dragon to death 1v1. An unprepared DM may be left with no way to counter this. It's the closest you can get to being immortal on the field of battle.

A non-Hasted Samurai can drop 10 attacks with Action Surge, then another 10 attacks if he gets dropped to 0 between turns, with advantage on 16 of those 20 attacks. If they all hit, that's good for somewhere between 200 and 400 damage, depending on what magic weapon he has. If it's an archer samurai with Sharpshooter, the damage numbers go up.

20th level artificers can Nope a lot of saves and keep the party from failing some, too.

20th level monks can be invisible, resistant to damage, and stun the heck out of things a lot. Anyone without truesight can't even see the monk. Add a subclass and maybe you get shadow teleportation or something on top of that. No fortress can keep a high level monk out unless it's a flying fortress far out of jumping range (and a simple broom of flying reaches that).

A high level Paladin with Resilient:Con can roll with a +15ish Con save and keep Circle of Power up, giving everyone Evasion vs magic and some other buffs.

Some of the 9th level spells are pretty good but get overlooked.
-Shapechange isn't permanent but lets you retain your casting, so you can be a 20th level wizard AND a beholder with an antimagic cone.

-Gate is pretty powerful, but mostly in terms of strategic power (move a few dozen giants, open a portal to the border between the Plane of Fire and Plane of Earth to flood an area with lava, etc.) so it gets left out of whiteroom discussions.

-The real value in True Polymorph is in object->creature. Defending a gate against Xykon and have 1 month to prepare? You have 1 month to turn a bunch of rocks into CR 9 Illithids. Sure, they go unfriendly after a while, but as long as you keep them from escaping, you have a lot of brain blasts enemies have to go through.

[HoboKnight]

@Unoriginal
Dude, relax. I am the DM.

@Mastikator
How is this done mechanically? I guess Archmage can do it too? So one turn he is a dragon, which is kinda meh at higher levels anyways and other turn he is an Archmage, which is useful, untill spell slots run out.

@Imbalance
Imagine a higher level campaign, where there is a massive dome in a huge mountain, full of Simulacrums. Then, just corpses. At the centre, there is immortal wizars with commoner stats, eternally screaming "Simulacrum, Simulacrum". As he tried his Simulacrum chain, gods got a bit irritated and Mystra took away his powers and cursed him for all eternity. There is no way to kill him.

@J-H
Thanks. None of this feels really be-all end-all. I would not mind my players using this, same as you did with Antipathy. Love the ruling.

[KorvinStarmast]

-The real value in True Polymorph is in object->creature. Defending a gate against Xykon and have 1 month to prepare? You have 1 month to turn a bunch of rocks into CR 9 Illithids. Sure, they go unfriendly after a while, but as long as you keep them from escaping, you have a lot of brain blasts enemies have to go through.
I had intended to substantially increase the Silver Dragon population of PhoenixPhyre's world (campaign 1) by using that aspect of the spell, but he as DM noped it for a very good (in-world) reason that had to do with where souls come from.

A dragon has a soul (it is a sentient creature). Based on how the magic and world building fit coherently into his world, I had to find a soul who was willing to be a young silver dragon. (I had designs on being a match maker since we had met a young copper dragon early in our adventures, and I figured he'd like a mate ... OK, as a level 20 bard, or course I was all about the drama and romance! Sue me! :smallyuk: )
I was able to find one, so when all was said and done off she flew with the name of the copper dragon and my personal endorsement of him in hand.
But.
I also had to clear this with the leader of a dragon clan (a loveable, alcoholic gold dragon whom we had allied with some levels previously). In the course of that discussion, I was warned that the dragon clans, in general, took a really dim view of humans messing about with procreating dragons outside the egg / family structure (think "objection to test tube babies" as a theme). My bard was warned IC not to do that again. And some good role playing was had along the way.

A wizard who has seen an adult gold dragon can true polymorph into one, wait 1 hour and become one permanently. The gold dragon is CR 17 and can shapeshift into a humanoid of CR 17 or lower, archmage from MM is a humanoid of CR 17 or lower. The ability is called "change shape"

Thus you can become a creature that can freely switch between wizard 20 and adult gold dragon.
Oh and dying just changes you back to your original form. Technically speaking, wizard-who-is-now-a-gold-dragon can change shape between and archmage (CR 12) and adult gold dragon. Could also do that with a Volo's archdruid for a change of pace. :smallbiggrin:
And that is a nice bonus; dying just turns one back into a level 20 wizard.

[Mastikator]

@Mastikator
How is this done mechanically? I guess Archmage can do it too? So one turn he is a dragon, which is kinda meh at higher levels anyways and other turn he is an Archmage, which is useful, untill spell slots run out.


You can freely switch between a dragon with 256 HP and a breath weapon that does 12d10 fire damage, a big fear AOE + ok amount of damage, or an archmage with most of your original spell slots (but not spells). The fun thing about the archmage is that it retains its hitpoints but gains advantage on saving throws to all magic.

Archmage doesn't have true polymorph, they have timestop. But as a gold dragon your shapeshifting ability lets you transform back and forth as an action at will. Either your DM will let you regain spellslots when you change shape, or when you long rest. Either way, being an adult gold dragon is pretty awesome, if you ever want to change back just ask your party members to reduce your HP to zero.

[sithlordnergal]

A wizard who has seen an adult gold dragon can true polymorph into one, wait 1 hour and become one permanently. The gold dragon is CR 17 and can shapeshift into a humanoid of CR 17 or lower, archmage from MM is a humanoid of CR 17 or lower. Thus you can become a creature that can freely switch between wizard 20 and adult gold dragon. Oh and dying just changes you back to your original form.

Oh you can do far, far better than that:

Step 1: Be a Bard, put Expertise into Persuasion, take Wish as one of your Magical Secrets

Step 2: Find an Ancient Gold Dragon

Step 3: Cast Glibness, use Persuasion to convince the Ancient Gold Dragon to turn into a Humanoid.

Step 4: Use Wish to cast Simulacrum as an Action

Step 5: Tell your Simulacrum to transform BACK into an Ancient Gold Dragon

Congrats, you now have an Ancient Gold Dragon Simulacrum. It is friendly towards you and obeys your spoken commands, moving and acting in accordance with your wishes and acting on your turn in combat.

Why it works: When a metallic dragon, such as a Gold Dragon, uses Shape Change, their creature type changes. This is the ONLY type of Shape Change that I know of that changes creature type. Once they turn into a Humanoid, you can cast Simulacrum. That simulacrum inherits all of that Humanoid's abilities, including the ability to turn back into an Ancient Gold Dragon.

For more shenanigans, you now have a CR 24 Simulacrum that you can cast True Polymorph on. It will retain the Simulacrum's personality, which it can be argued that the Simulacrum's personality is "Friendly to you, and obeys you.", though that second part is debatable. You do not need to see a creature to True Polymorph into one. Congrats, your Simulacrum can become a CR 24 to 21, with full HP.

----


Other broken things:

Wanna run as fast as Sonic? Eldritch Knight Fighter 3 / Elk totem Barbarian 3 / Monk 14. Go Tabaxi, take Mobile. Base speed is 65, cast Longstrider then rage for +25 movement. You now have a base speed of 90. Tabaxi speed doubles it to 180 for a round. Next Dash, Bonus Action Dash, Action Surge Dash, and move for 720 movement in one round.

Of course, by level 20 you hopefully have some magic items. So lets say you find Boots of Speed and an Eagle Whistle. Boots of Speed doubles your movement, and Eagle Whistle gives you a fly speed equal to double your walking speed. Use them both, that's a fly speed of either 270 or 360, depending on how your DM stacks movement speed. Tabaxi speed will make that 360 or 720. Then you can Move, Dash, Step of the Wind, Action Surge Dash for a grand total of either 1,440 feet in a round or 2,880. And heaven help your DM if you have a Potion of Speed or someone casts Haste on you. You don't just do dungeons, you speed run them. Literally.


Wanna do big damage instead? May I suggest Tempest Cleric 2 / Scribe Wizard 18. Take Crusher and Elemental Adept, trust me they'll help. For pure damage, few things beat a max damage Meteor Swarm that deals Lightning Damage that can't be resisted. But if you have a way to guarantee a crit, might I suggest a max level Witch Bolt? Its only 216 damage instead of Meteor Swarm's 240, and it is single target...but if you have a guaranteed crit then it bypasses something like Legendary Resistance which would have Meteor Swarm's damage. Plus it won't murder your allies.


And finally, just Moon Druid.


EDIT: So, I know there are technically dragons that are an even higher CR now. but I feel like you'd be pushing it if you managed to find one of those dragons. But hey, if you do, potentially get yourself a Simulacrum Marut. 120 damage per round via two attacks that can't miss, 400+ hp, its a good investment. You just need a CR 25 or higher Metallic Dragon.

[No brains]

I feel all the ways you can break the game at level 20 can be made into a musical number. One with lots of prancing and twirling on streetlights.

It's not that impressive, or even useful, but a high-level trickery cleric can use mirror image and invoke duplicity to apparently have backup from 14 of themselves. Maybe not breaking in the traditional sense, but you can cheese of your DM from having to manage 15 of you on the battlefield at once.

[LudicSavant]

Superman Phone Booths: You basically toss a ton of glyphs of warding inside an extradimensional space (or really, since this is high level, you can just teleport about), and then have them stack a ton of Concentration spells on you (ignoring the usual stacking limits). Expensive but gold is often little object at level 20, and it's extremely powerful.

Illusory Reality + Mirage Arcane + Malleable Illusions in general.



-Gate is pretty powerful, but mostly in terms of strategic power (move a few dozen giants, open a portal to the border between the Plane of Fire and Plane of Earth to flood an area with lava, etc.) so it gets left out of whiteroom discussions.

Likely the scariest (and least intended) thing Gate can do is that it can kidnap someone from anywhere with no save. If you know the BBEG's name, you can summon them into a ridiculous deathtrap of your choosing. And vice versa -- if a BBEG knows a player's name, they can basically just throw them into the sun.


Simulacrum spam has an endpoint in terms of spell slots available, unless the DM generously rules that Sims start with no spell slots expended. No such ruling is required; you just need to have them use it in the right order, on the right targets, to prevent the depletion (obviously, this shouldn't be allowed).


High end barbarians, especially Zealot barbs, have a very short list of ways to kill them, most of which require specific spells such as Sleep, Calm Emotions, and Power Word: X that are not typically prepared. Otherwise, they can straight up facetank a dragon to death 1v1. An unprepared DM may be left with no way to counter this. It's the closest you can get to being immortal on the field of battle.

Eh, there's a lot of stuff that bypasses death gates or incapacitates you for long enough for rage to run out at level 20. I find a lot of other things more difficult to kill than Zealots.

[Unoriginal]

And vice versa -- if a BBEG knows a player's name, they can basically just throw them into the sun.

"BBEG learns of the players and summon them to deal with the figures who were actually controlling the heroes all along" is the end of The Gamers: Hands of Fate.
.

[No brains]

Pro-Tip for DMs: Having your antagonists live in areas with Forbiddance and Mordenkainen's Private Sanctum helps prevent Gate shenanigans.

[Thrormathan]

Or just moon druid 20 -wildshape into mammoth every bonus action for unlimited HP-

[Nagog]

Outside of the usual, Arcana Wizard at level 20 can have Wish and guarantied Divine Intervention. Not to even mention all the cool stuff you get as a level 20 Cleric (and the Potent Cantrip+Shillelagh+GFB/BB combo)

[RSP]

You can freely switch between a dragon with 256 HP and a breath weapon that does 12d10 fire damage, a big fear AOE + ok amount of damage, or an archmage with most of your original spell slots (but not spells). The fun thing about the archmage is that it retains its hitpoints but gains advantage on saving throws to all magic.


Interesting question:

Say said lvl 20 Wizard casts True Polymorph and changes into a dragon. A month goes by and they’re dropped to 0, True Polymorph ends and they revert to their original Wizard form.

Are they down the 9th level slot they used to cast TP in the first place?

On first thought, I’d say yes: while they had long rests while a dragon, they didn’t have the Spellcasting feature that allows the recovery of spell slots on a long rest.

Could be missing something though.

[KorvinStarmast]

Outside of the usual, Arcana Wizard at level 20 can have Wish and guarantied Divine Intervention. Not to even mention all the cool stuff you get as a level 20 Cleric (and the Potent Cantrip+Shillelagh+GFB/BB combo) I think you meant Arcana cleric. :smallsmile: