House Rule – Upcasting Enlarge / Reduce to extend duration

The party is deep into my 5e-updated classic Greyhawk Giants series.

The hill giants and their orc and goblin minions have attacked the Sterish city of Headwater and have taken about a quarter of the city. The party is about to embark on a mission to go behind enemy lines, kidnap and assassinate a stone giant who is critical to the hill giants’ city / siege offensive as being their only trained engineer. While the party’s patron recognizes that the stone giant needs to die, she also recognizes that at present the Stone Giant Thane has not joined the giant alliance and wants to keep it that way. Thus, she is requesting that they carry the body of the slain giant honorably back to his Thane in an effort to preserve a fragile peace between the humans and the stone giants. I would like the party to be able to accept this mission, without it becoming either a logistical challenge involving wagons and draft animals, or without loaning them a portable hole.

Instead, I would like to provide them with a version of the Enlarge / Reduce spell which is in all aspects identical to the original except that it can be upcast to extend the duration.

I figure the giant is 17 feet high and 1000 pounds; after reduce it would be 8.5 feet and a manageable 125 pounds.

For this version of Enlarge / Reduce I am proposing that:

When cast at 3rd level against living creatures, it lasts 10 minutes

When cast at 3rd level against objects, it lasts 1 hour

When cast at 4th level against living creatures, it lasts 1 hour (similar to polymorph)

When cast at 4th level against objects, it lasts 8 hours

When cast at 5th level against living creatures, it lasts 8 hours (much less than geas)

When cast at 5th level against objects, it lasts 24 hours

The party Wizard is currently 8th level and getting close to 9th. Requiring her to use both her fourth level slots and maintain concentration for the duration of travel every day in order to move swiftly and stealthily into the mountains with the body is just the right level of challenge for the group.

My only concern is that allowing this version of the spell to the party wizard permanently will have some unforeseen interaction with some other spell, ability, or item that I will later regret. This question, for example, asks about upcasting enlarge to permit two changes in creature size, and answers identify the interaction with levitation and grappling being problematic. I am interested in a similar troubleshooting review.

Does a Duergar Spy’s Enlarge action double its damage dice from its Sneak Attack trait?

In the module The Forge of Fury (tiny spoiler) there is a Duergar Spy creature. Its statblock is on p. 234 of Tales from the Yawning Portal.

I am interested in the way two of its features interact with each other, Enlarge and Sneak Attack. If the Spy qualifies for a Sneak Attack while Enlarged, are the damage dice added from the sneak attack doubled?

The duergar spy’s Enlarge action says:

For 1 minute, the spy magically increases in size […] While enlarged, the spy is Large, doubles her damage dice on Strength-based weapon attacks, and makes Strength checks and saving throws with advantage.

Its Sneak Attack trait says:

Once per turn, the spy can deal an extra 7 (2d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally that isn’t incapacitated and the spy doesn’t have disadvantage on the attack roll.

The spy has a Shortsword attack. A Shortsword is normally a finesse weapon, meaning one can use either Str or Dex for to hit and damage. The stat block suggests the Spy uses Dex, but explicitly applies Enlarge to it (the spy has a Str mod of +0 and a Dex mod of +3).

Shortsword. Melee Weapon Attack: +5 to hit. Hit: 6 (1d6+3) piercing damage, or 10 (2d6+3) while enlarged.

How should Duergars enlarge power and Squeezing into cramped spaces interact?

The actual RAW rule for the Duergar’s enlarge is:

Enlarge (Recharges after a Short or Long Rest). For 1 minute, the duergar magically increases in size, along with anything it is wearing or carrying. While enlarged, the duergar is Large, doubles its damage dice on Strength-based weapon attacks (included in the attacks), and makes Strength checks and Strength saving throws with advantage. If the duergar lacks the room to become Large, it attains the maximum size possible in the space available.

So, in abbreviated form, I see these effects while enlarged:

  • Status Change: Size is Large.
  • Benefit: For Strength based attacks, double the base weapon damage dice.
  • Benefit: Advantage on Strength checks and Strength save.
  • Special Condition: If not enough room to become Large, becomes maximum possible size instead.

It is this last point, and especially how it interact which with the 3 others, that we are confused about.

Also, here is the rule for cramped spaces:

SQUEEZING INTO A SMALLER SPACE

A creature can squeeze through a space that is large enough for a creature one size smaller than it. Thus, a Large creature can squeeze through a passage that’s only 5 feet wide. While squeezing through a space, a creature must spend 1 extra foot for every foot it moves there, and it has disadvantage on attack rolls and Dexterity saving throws. Attack rolls against the creature have advantage while it’s in the smaller space.

Given the situation as detailed in my question above (i.e. duergar decides to enlarge while in a 1 square wide corridor i.e. a 5 feet wide corridor), what should actually happpens, as per RAW?

[A] There is not enough space for the Duergar to actually enlarge to Large size, so the Duergar remains Medium size. Thus, as a Medium creature, it is not Squeezing into a Smaller space. Also, given that it is not Large, it doesn’t get it’s other Duergar enlargement’s damage and Strength benefits.

or

[B] The duergar enlarges somewhat to the maximum possible for Medium creatures, becoming noticeably larger but still "barely under" the limit for actually becoming squeezed (kinda like how a Goliath is still a Medium creature but still has a much bigger "build" anyway). But, as there is not enough space for the Duergar to actually truly enlarge to Large size, thus the Duergar remains a Medium size creature. Thus, as a Medium creature, it is not Squeezing into a Smaller space. However, the Duergar still gets all of his other bonuses from his enlargement (weapon damage and strength advantage), because those benefits are dependent upon the activation of the enlargement power, not on the duergar effectivey really becoming Large size.

or

[C] The duergar enlarges to Large size because it is possible for him to do so anyway: "it attains the maximum size possible in the space available" meaning that it is indeed posssible for a Large creature to exist in a 5-feet wide tunnel, despite the cramped conditions. Thus, the "maximum possible" to exist there is not "Medium", but it is instead "Large + squeezing". Not only does the duergar gets all of his bonuses from being enlarged, but it is also now Squeezing into a smaller space.

So, which is it? DM + players each have their own ideas on how to resolve this, seemingly on opposite ends of the spectrum. We argue the duergar should become squeezed as in [C], thus getting the penalties. Aka "This is really a bad dungeon design for them, all the rooms and corridors where there could be any battle should instead be made to take advantage of their Large size in combat instead". DM is the complete other way as you will see below.

Of course the DM ultimately decides, but we wanted to know what the actually RAW ruling is because a lot more duergars are going to be fought over the next few sessions, we have just entered into a huge dungeon and that dungeon is really seeminggly going to be a big dungeon crawl full of tiny tunnels and tiny rooms, full of duergars all the way to the bottom level.

But it actuallly goes further than even that.

The party is actually good at being fast & sneaky, so the PCs can relatively easily surprise the duergar while they are in a tiny room, to immediately enter the room and position ourselves so that the duergars simply do not have any free 10×10 feet area for them to easily become fully Large size. So, what happens then, when the duergar go into enlargement?

[D] Exactly the same thing as in the 5-feet wide tunnel above (either [A] or [B] or [C]). The PCs are treated as much as "solid obstacles" as the walls are. That is the players’ opinion on things.

or

[E] As the duergar enlarges, it also automatically pushes away any PCs into nearby empty spaces. The player decides which way he is pushed back (this is not a Shove Action made on purpose, after all), with a Strength Save to try to resist the push (duergar ability DC being 8 + 2 Proficiency + 2 STR = DC 12). If pushed and the only way to be pushed back is right into a hole, the PC falls, with a DC 12 Dex Save allowed to hang onto the ledge. This is a "middle ground" approach we tried to negotiate.

or

[F] Same as E, however since the enlargement is "magical" in nature, it pushes back so strongly that it is the duergar’s space that always takes priority, forcing PCs to be the ones pushed not only backways but even sideways too. Basically it works EXACTLY like a free multi-target Shove that is always automatically succesfull, without any opposing resisting check. So in other words it is the duergar who chooses which way we get pushed, even to the point of being forced to end up with 2 or more PCs forced into the same space. Thus, not only does the duergar end up with zero penalty for cramped space, but it is the PCs that end up being the ones that are all squeezed up! And if 3 or more PCs are forced into the same space, they get squeezed so much so that they automatically fall Prone, can’t attack at all, and have to Crawl to get out of the "body pile", provoking an Attack of Opportunity in the process. That is the DM’s stance.

The DM retroactively said that that dungeon has lots of small tunnels and rooms on purpose: he actually built that duergar-built "fortress dungeon" fully with "Interpretation F" in mind.

Also, the DM made the duergar enlarge power "free" to use and not an "Action" to use. Basically, duergar can grow enlarged and immediately attack on their same turn. Monster Manual however seems to say otherwise? Anyway, that dungeon is full of very deadly traps that the perma-invisible duergars (they constantly short rest all day long to keep invisible, because you can somehow maintain your Concentration fulll time during a short rest?) just enlarge at exactly the right moment in order to auto-shove us into ridiculous damage traps (up to acid and lava pits and non-lootable vorpal wall blades and also "mordenkainen disjunction" traps), with of course being allowwed to make an attack too (making falling into a pit trap, or taking the trap’s weapon damage a second time "as you get whacked all around inside the swift moving blades of the trap even more", becoming a neear certainty (DM makes the save DC based on the total damage they deal). Basically: Big Ouchie.

While a DM is allowed to run his campaign as he sees fit, he also insists that he is applying the rules "by the book", so… as per RAW, is he really in any way in the right here? Please help?

Thanks!

Cast Enlarge on a vial of acid then Catapult it. 8X damage?

My wizard wants to do a spell combo, it will take two turns.

Enlarge/Reduce then Catapult

  1. Cast enlarge on a vial of acid. It weighs 1 pound and per the spell description it will grow to 8 pounds. So it will have 8 times the volume and therefore it will do 8 times the damage. 16d6 instead of 2d6.

How to deliver it?

  1. Cast catapult on the large vial at level 2, because it weighs 8 pounds now, doing 4d8 damage + 16d6 acid.

A whopping 128HP max. Average 74.5 (if it hits)

Does this work? If not, why?

Magic Stone + Enlarge [duplicate]

Can a thrown magic pebble be a target to the enlarge spell? For that matter, can anything from an arrow to a hurled table become enlarged while in mid-air and if so how would you suggest fantasy physics would work on this?

The enlarge spell states that the target doubles in all sizes but the weight is times eight. Would the (stone, for example) maintain its velocity and hit the target with 8x its weight? We all know that F = m*a.
How would you suggest to handle this DMG wise?

As always thanks in advance my fellow Dungeoneers.

How can non-humanoids benefit from enlarge person?

I am playing a tiefling who is a native outsider. During play it has come to my attention that enlarge person will not work for me because I am not a humanoid. This seems like a silly restriction since there are many non-humanoid races presented for us to choose from. So how can I benefit from enlarge person or a similar spell (similar as in duration and spell level). Yes in theory I could use the rules for creating a new spell but I am hoping that there is already something that exists.

It seems that I was not clear enough. I am looking for a solution that will work for all non-humanoids. Not just tieflings.

What should happen if you cast enlarge on an explosive?

My thief player set a bomb and hid with a wizard player who was going to ignite it from afar with magic when the guards got close to it. While they waited the wizard got the bright idea to cast “enlarge” on it and turn 1lb of explosive into 8lb of explosive.

I winged it a bit and went with the explosion being twice as large (hitting everyone in 10 feet instead of 5) and dealing an extra 1d4 damage, though that’s supposed to be the effect if it’s a weapon.

Under RAW is there proper way to handle an ‘enlarged’ explosive?

What effects would casting Enlarge on a bag of holding have?

I was watching a video about underrated spells, and one of the spells listed was Enlarge/Reduce. One of the examples given was reducing a large, heavy statue, then the party carrying the statue away, and my mind leaped to “wait, what if you cast Enlarge on a bag of holding?”

My main thoughts are that it would increase its capacity for the duration of the spell, and possibly its weight limit as well, but I’m not too sure

Do unarmed strikes count as “weapon attacks” for purposes of features like Enlarge and Brute Force?

According to Sage Advice:

Unarmed strikes have always been weapon attacks. Here’s where the confusion comes in: your unarmed strike (fist, elbow, knee, butt, etc.) is not considered by the rules to be a weapon the way a longsword is a weapon. But the rules let you make unarmed weapon attacks anyway.

This ruling is clear for features like Rage, but less so for something like Enlarge:

The target’s weapons also grow to match its new size. While these weapons are enlarged, the target’s attacks with them deal 1d4 extra damage.

An unarmed strike qualifies as a melee weapon attack, but does it qualify as a “weapon” under these circumstances? It’s relatively obvious for effects that specify a weapon as an object, like the Forge cleric’s Blessing of the Forge, but this seems like a grey area.

Enlarge / REduce spell cast on a creature that has its hands and feet tied up to trees around him

The Enlarge/REduce Spell indicates that when you enlarge a creature and there is not enough space available, it just grows to maximum possible size given the space available. This effect seems to maybe temporarily trap a creature but will not cause damage to it. On the opposing effect, if you tie a creature’s limbs to trees in ‘star’ shaped fashion, then cast reduce on it, would the limbs effectively pop out as the creature shrinks or would just the spell fails to shrink the creature because of the rope’s resistance preventing the creature to shrink more without tearing it apart.

To me this is one of the worst written spell in history… can anyoone bring some clarification ? something I am missing here ?