So I'm playing a homebrew 5e campaign, and I have one player playing as an Artificer. Who apparently, has infinite acid.

This artificer has taken to melting any obstacle with acid, locked doors, bars they were meant to find a switch to open, chests.

I'm struggling to not be spiteful and say "Your acid ruins everything in the chest!"

What on Earth do I do?

  • \$\begingroup\$ Send him to see the act end boss Ken Kesey if acid is the problem. \$\endgroup\$ Commented Nov 15, 2017 at 4:05

10 Answers 10


Different materials act different to different acids.

So he may need a different acid for each thing he tries to destroy. I don't know what the exact specification of an artificer is, but knowing all materials and their properties at a glance seems a little overpowered. You could make it significantly harder on him by required a skill-check to properly identify the material he's trying to attack. Potentially followed by a skill-check to construct the most effective acid possible. Results of these skill checks could influence time and effectiveness.

Acid destruction is rather slow and subject to environmental conditions

In general, acids just react with surface material that the acid can touch. They don't necessarily even destroy the material as much as partly dissolve it / partly transform it into gas / partly transform it into another solid. In case the acid leaves some kind of solid residue (as is the case with most metals out of the alkali range) that can slow or stop the reaction by stopping the acid from getting to the material. Your artificer would then have to brush or chip away at the waste products before applying more acid (rinse and repeat). This can take quite a while. You can significantly increase destruction speed by knowing and influencing environmental factors that change corrosion types and speeds and that help with metal ions going into solution.

You'd need to check out actual materials science to see how fast acids burn through which materials under which environmental conditions, but it's generally not easy and not fast. Few quick examples: Stainless steel beams break faster in seawater than normal steel (they rust in a specific pattern that makes deep cracks compared to the normal steel beams that rust more evenly and hence hold out longer). Steel gets destroyed faster by nitric acid under the influence of salt. http://www.sciencedirect.com/science/article/pii/S0010938X97000929 http://www.wisegeek.com/what-are-the-effects-of-sulfuric-acid-on-steel.htm


  • Destroying materials with acids is easy. Doing it fast and controlled is hard
  • Knowledge of the material is required. Maybe do a skill-check.
  • Knowledge of acids is required. Maybe another skill-check.
  • Knowledge of the conditions needed for effective and fast solution and/or corrosion is required. This is the hardest part, both to know and to execute. The artificer might need solvents, catalysts and energy (heat, electricity, radiation) to speed up the process.

This Isn't a New Problem...

The Acid does a number of damage to the objects following what the rules say. This damage is no different from a weapon damage, game wise. This question is the same as asking "My barbarian smashes everything". In that regard, this might be a duplicate, except this is playtest material instead of a core class.

Acid in DnD isn't special. It does damage just like any other weapon. You'd solve it the same way as raging barbarian tearing through stuff.

Object Have AC and HP per RAW...

Objects in 5e, have HP. Look up in the PHB or SRD the HP of chests and doors, and from the listed HP numbers for various things, figure out how much HP the other stuff he's splashing with acid. I doubt the bars would melt with reasonable HP.

A critical hip might burn some mundane objects in the chests, and I'd calculate that out, too, to make sure.

Object AC

$$ \begin{array}{l|c} \text{Substance} & \text{AC} \\ \hline Cloth, paper, rope & 11\\ Crystal, glass, ice & 13 \\ Wood, bone & 15 \\ Stone & 17\\ Iron, steel & 19\\ Mithral & 21\\ Adamantite&23\\ \end{array} $$

Object HP

$$ \begin{array}{l|l|l} \text{Size} & \text{Fragile} & \text{Resilient}\\ \hline Tiny (bottle, lock)& 2 \; (1d4) & 5 \;(2d4)\\ Small (chest, lute)& 3 \; (1d6) & 10 \; (3d6)\\ Medium (barrel, chandelier)& 4 \; (1d8)& 18 \; (4d8)\\ Large (cart, 10'\text{x}10' window)& 5 \; (1d10)& 27 \; (5d10)\\ \end{array} $$

Unearthed Arcana is play-test Material -- Tweak As Needed.

Lastly, remember the Artificer is playtest material. I personally think this problem isn't a problem of the class, but one of player-DM relation -- but any problem in playtest material can easily be remedied by a rule change.

Inform Players Ahead of Time

If you change the way it works (either Object HP as RAW or a rules change), don't spring it as a surprise in game. "Hey, this thing is broken in our game. We're going to try a change tonight. I'm doing X differently, and see how it works."

No More Mr. Nice Guy. Every DM's Favorite Surprise Monster

I don't know why I didn't add it at the time, but one solution you can reach for if talking, using the HP rules, houserules all fail you. It is: The Mimic. As he goes to splash the acid on the door or chest, roll the save for the mimic. Then, have him role initiative. And look at that, the mimic is very happy about that magic bag you just pulled the acid out of, as it likes having valuables and magic items to lure in prey.


Ask yourself: "why does not every person I know (in real life) carry lots of acid? It seems so handy!"

Your answers to that, which may include:

  • acid doesn't actually melt everything*;
  • acid that melts things can be very hard to control in application;
  • acid that melts things is hard to store, transport, and handle;
  • acid can take much longer to deal with locks than, say, a key;
  • acid can create noxious fumes;
  • acid generally irrevocably damages things, which isn't always desirable;
  • acid can be hard to procure in large quantities;
  • &c. &c. &c.

Your artificer doesn't have to worry about procurement or storage, presumably. But the rest (and whatever else you think of!) could all be reasons that a PC might eschew the use of acid, too--use them to inform your world, your designs, your rulings.

* - The stuff described at the bottom of this WhatIf basically does, though. A quick scan of the linked articles should provide you all the narrative fodder you need for D&D's "step 3": The DM narrates the results of the adventurers' actions.

  • \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$
    – mxyzplk
    Commented Jul 7, 2017 at 3:41

Create Different Obstacles

You seem to be presenting your characters with lots of "Lock-and-Key" problems. These types of problems don't always require a literal key, but more often a particular item that solves an issue that impedes progress. This player has a sort of "Master Key" that works effectively on a wide array of "locks," literally anything that can be melted with acid. These forms of locks are not the only things that can impede progress, however.

Consider when planning your locks what may impede progress without being solved by the Artificer's acid. Thick stone walls, moveable only by a magical artifact might be a possible solution. Another might be a powerful sphinx asking a riddle, or another powerful beast who wants a particular item, in order to allow the group to proceed. Other locks can block progress less literally, as certain information may be needed in order to proceed, rather than an item. Perhaps a maze blocks progress without a map, and players need to find that first.

Remove the Key

The Artificer can only produce his acid so long as he has his satchel. If there's a puzzle or dungeon you have planned which may require literal keys, or some other solution which the acid seems to solve too easily, consider stealing the Artificer's satchel from him. This should be used with extreme caution, however, as it's his primary source of damage as well. I'd also suggest stealing gear from other players if you are to attempt this solution, as to prevent the Artificer from feeling singled out. Additionally, be sure to allow a way for any and all gear to be recovered after the completion of this dungeon/adventure.


There's a few things you can do.

  1. Remember that glass is (generally) unaffected by acid (though there are acids that will eat away at glass). But also have the glass be sturdy enough that it can't simply be shattered, either (thus causing the characters an alternative way of doing things).

  2. Put obstacles in the way that acid won't help with (a pit for instance) or have something that actually eats acid. (For instance if the character is trapped in the stomach of something… the acid would start breaking HIM down (or later down in the digestive track aid in his own digestion!)

  3. Have the acid do something that's unexpected and cause more problems. For instance in the door scenario, you might simply have the lock and its opening mechanism fuse together, thus the door becomes inoperable through normal means.

  4. Do exactly as you said. If there's important contents inside the chest, they're simply destroyed.

  5. Let the acid use come back to bite them. Let's say that he uses acid in battle… but forgets where he threw it. Suddenly he steps where he threw it and now he has a disadvantage because there's a hole in the floor! Or they cross a rickety rope bridge, and to prevent others from following he uses acid on the ropes. Now the party's stuck with a very hungry dragon… and the PCs have no way of escape!


I think most of the other answers cover most of the possibilities, but I would like to add that it can really suck as a player to take away or nerf their class abilities without extraordinarily good reason. As such, I think it's very much worth it to ask whether you really have a problem or is this a creative solution.

Your described problem is not really any different than a barbarian with an axe and the will to use it or a sorcerer using fire bolt endlessly. In our current Strahd game, my character has a crowbar and uses it whenever leverage seems helpful (which is a lot if you put some thought into it). These are all, effectively, unlimited use problem solving devices.

Your specific question asks

This artificer has taken to melting any obstacle with acid, locked doors, bars >they were meant to find a switch to open, chests.

I'm struggling to not be spiteful and say "Your acid ruins everything in the chest!"

This isn't necessarily a bad thing to do as it's a reasonable consequence of using acid. If your barbarian was using his unlimited battleaxe on chests, he'd probably break what was in the chest as well. Same with a sorcerer using an unlimited firebolt to bypass the problem.

If your concern stems from locks being bypassed, you should ask if your problem is still present if a Rogue used a crowbar or a thieves' tools to bypass the lock. Bear in mind, that destroying the lock doesn't necessarily remove traps that might be present, so you always have the opportunity to catch them with that, but you'd also have the same chance with a Rogue.

In summary, your artificer has a brute force method. Sometimes it's the perfect solution, other times it will cause problems, but overall, I'm not sure you have a problem so much as a 'working as intended'.

The means of XP gain is by overcoming obstacles. More often than not, there's more solutions to overcoming an obstacle then the one that you planned for as a DM.

As a final note, I would point out that some things of substantial size can have a damage threshold which essentially functions like hardness from 3.5 (see page 247 in the DMG). I wouldn't use it excessively, but it can provide a means to ensure that something can't simply be bypassed using the acid trick. Perhaps a massive portcullis on a castle's drawbridge has Damage Threshold 20 so only a particularly high level artificer can even hope to harm it.


Destroying objects is one of the things acid (and sonic/thunder) damage is meant for. And Alchemist's Acid in particular emphasises this.

Consider as well that the Artificer really doesn't get much out of its class features, and is barely playable without heavy houseruling. Little things like easily destroying objects are one of the few sources of creativity available to the Alchemist.

Were I to play an Alchemist, I too would be making every effort to melt my way through every obstacle in my path. 'When all you have is a hammer', and all that.

But, Alchemist's Acid is indescriminate. It's an area attack that cannot be channeled or controlled. There will be massive pits in the floors and walls and perhaps even the ceiling (yay difficult terrain). It will melt through clues and loot. Definitely play up the collateral damage this strategy causes. I know that in combat I would definitely prefer Alchemist's Fire under most circumstances, simply because it only damages creatures and is therefore vastly easier to control.

Also consider that different objects have different hardnesses and hit points. The wooden floor under the safe is likely to fail long before the safe itself, for example, and this may even result in the party being trapped under tonnes of rubble. Or there will be things too durable for the acid to damage at all. Even when smashing one's way through obstacles, finesse and careful planning should never be underestimated.

Lastly, D&D is a game of resource management, and one very quickly learns that time is by far the most important. While often destroying everything may be fast, the prep and planning for various safety concerns (both for the party and the loot) may take longer than just doing things 'normally'. Or maybe the lack of subtlety means the villain notices the party's actions (not that they're hard to miss) and she starts preparing. After a certain point, the DM has to put the plot on a timer to give the party any kind of challenge, and a lack of finesse is a good way to get, say, the town guard on your case and wasting your time.

TL;DR: This is intended behaviour, but that doesn't mean that this should go on without consequences.

EDIT: It seems I misread the ability as being a splash attack like Alchemist's Fire when it is in fact a single target effect. I endorse this as homebrew (and I'm not going to edit the above for accuracy as an object example of why (and also because I'd need to restructure and rewrite the whole thing)). The Alchemist could honestly use the extra damage considering how high enemy Dex saves tend to be at high levels, and it would add a lot of tactical and strategic depth to both the ability and the game as a whole. The resulting lack of single target damage might be too much of a nerf though (my instinct is to patch that with the addition of, say, Alchemist's Frost).


Talk to your player is the short answer.

If you find your players are being one trick ponies and using the same thing to overcome all challenges then the best way to handle that in my experience is to talk to them. Tell them that they shouldn't use the same thing over and over to solve problems. D&D is in part about players playing ball with the DM.


The Alchemist has a class feature called acid that, when translated out of mechanical terms, basically says: "If there is an object, you can destroy it, if you want, relatively quickly and at no cost to you". You then present the player with a situation that loosely translates to: "There is a thing you want-- but wait! A non-valuable mundane object is in your way!" You want the player to be stymied by this object, and forced to deduce the planned MacGuffin so as to get the thing they want, but instead the player uses their class ability, "Objects in my way aren't a problem", and thus the plan is ruined.

There are exactly three potential solutions here. Either the player needs to not have a character with the ability "generic objects in my way are not a problem", you need to present puzzles that don't easily boil down to "a generic object is in my way", or you need to accept that the problems will all be trivially solved.

Option one means not letting your player play an alchemist. Have them play a different class that doesn't have an ability that, in summary, is "objects in my way are not a problem". Besides the alchemist, you probably also want to ban any and all varieties of Rogue, especially the core 'Thief' variety. Fighter is probably the best class for players to have, so as to not disrupt your dungeon design, and you should ban backgrounds that grant proficiency in thieves' tools as well as the use of such tools itself. Be sure to be clear with your players about why you are banning these things-- they make it too easily possible for PCs to bypass your traps/obstacles without doing so via the expected/planned solution-- both so that they can help out with avoiding undesirable behavior during sessions and so that they can decide not to play in the campaign if the playstyle you are mandating is not one they enjoy.

Option 2 means practice, practice, and more practice on your part. You have to come up with cleverer traps and obstacles and dungeon designs so that this trick doesn't bypass them all. Being able to destroy objects you don't care about is pretty nifty, and it's likely your first couple acid-proof set-ups won't be quite as acid-proof as you think. It's okay to still include some traps/obstacles that aren't acid-proof so that your alchemist can get to use the ability if they remember and decide to, but you will want to make sure that at least one obstacle in each set of things you plan can't be solved that way. Combat is a pretty easy out here, but more complex traps where destroying something that at first appears threatening would result in disastrous consequences is a better example solution-- I doubt your campaign is combat-free at present and the mechanical separation makes it easy to ignore that Acid doesn't solve combat the way it solves other problems. To help out with this solution option, I have some example progress-preventing obstacle types that should be resistant to acid use:

  • The aforementioned object-that-looks-bad-but-is-good situation. For example, a sealed door that is holding back a supply of water (drained when the doors are opened properly) sufficient to flood several rooms and potentially drown the party.
  • a non-object non-creature obstacle blocks passage. For example, a cloud of harmful gas fills the hallway ahead (make sure it's lighter than air or the alchemist will just burn a pit in the floor. Burning a pit in the ceiling risks collapsing the passage). The prophylactic or a source of powerful winds lies elsewhere in the dungeon.
  • An NPC only allows passage through once certain conditions are met. For example, the Elder Earth Elemental only allows passage into the temple if the party has been authorized by a priest of the Cult of Gravity. The alchemist could burn down the tungsten door to the temple, but that wouldn't help the party get inside.
  • a valuable treasure item blocks passage. For example, the locked door to the treasure vault of the ancient dwarven kingdom is made of solid voratun, insribed with the as-yet-unknown history of the secretive people, and glows with an intracite weaving of both arcane and natural magics thought impossible by many learned minds of the modern age.
  • time pressure prevents acid from being fast enough (keep in mind this will stop pretty much any other method of breaking stuff as well-- acid deals a good amount of maximized damage that just automatically happens regardless of defenses and such. It's hard to beat that efficiency). For example, a moving platform moves along a track from a hallway over a pit of lava past a door in the wall and into a wall of fire for several rounds before returning. The alchemist could burn through the sturdy iron door, but it would take several rounds and by that point the party would be toast. Note that thieves' tools can probably still solve this encounter.
  • distance stops the acid from reaching. For example, a 40' chasm above a swift river stops the party's passage. A raised drawbridge is on the opposite bank, held up by a counterweight.

Option three is included just for completeness.

  • \$\begingroup\$ This is a great answer, but I think option 3 could be expanded on. Sometimes, it's okay for a character to use the abilities they have on tasks that they're perfectly suited for. If you've got a setup where there's supposed to be months of difficulty getting food and water, and the party has a druid who solves the problem with goodberry, yay for the party. Someone has dedicated significant resources to solving that problem, even if the end result is that it looks like the challenge is sidestepped. Maybe later when the party is attacked by undead, they'll wish they had a cleric instead. \$\endgroup\$
    – mattdm
    Commented Nov 14, 2017 at 15:53
  • \$\begingroup\$ @mattdm that's option 2 if later there's a problem that can't be solved with goodberry. Option 3 would be like a tabletop version of this, where the DM just continually presents problems trivially solved by Acid and then the player uses acid and then they do it again, but the DM has conditioned themself to have fun nonetheless. This is included because without that option the statement that the presented options form the complete solution space would be wrong. \$\endgroup\$ Commented Nov 14, 2017 at 20:03

Complementing Pyrotechnical's answer, the UA Artificer PDF (version 20170109) says:

Alchemical Acid. As an action, you can reach into your Alchemist’s Satchel, pull out a vial of acid, and hurl the vial at a creature or object within 30 feet of you (the vial and its contents disappear if you don’t hurl the vial by the end of the current turn). The vial shatters on impact. A creature must succeed on a Dexterity saving throw or take [(Artificer level + 1) / 2] d6 acid damage. An object automatically takes that damage, and the damage is maximized.

Specifically, the Artificer can summon a vial and throw it, causing Xd6 damage, or the vial disappears by itself just before the beginning of the alchemist's next turn. So barring a multiclass Artificer N/Fighter 2 using Action Surge, the acid will disappear before they can draw another flask to increase the amount in existence at any given time.

This puts a cap on the maximum amount of acid that can be present at a given time, not unlike a spellcaster's cantrip like Acid Splash (although the damage is clearly overpowered at high levels, compared to a cantrip). So give it resistance to acid and a sufficiently large door can obtain immunity to the acid of a low-level Artificer through Damage Threshold mechanics.


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