Enlarge + Enlarge = Huge? (two different sources)

Question

Long story short, one of my players has a bodice that allows her to increase her size (as per the Enlarge/Reduce person, but only the enlarge part of the spell).

Another character asked if he could cast enlarge on her after she was already Large. I liked the idea but wasn't sure what the bonuses would be so we decided to table it until further discussion could be done.

My thought is that it can be done, (just for fun, not for shenanigans) and one would simply double the numerical value of the spell. (increase by 2 size categories, from medium to huge, quadruple height, x64 weight, weapon attacks deal an extra 1d8 dmg.)

What are your thoughts on this?

Answer 1

There are two possibilities

The bodice allows the wearer to cast Enlarge

Unfortunately, you cannot combine the effects.

The effects of different spells add together while the durations of those spells overlap. The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect--such as the highest bonus--from those castings applies while their durations overlap, or the most recent effect applies if the castings are equally potent and their durations overlap.

So if the bodice is just casting the spell, it won't work. Now, it's entirely possible that as a DM you can rule that since it's not quite the same spell, enlarge vs enlarge/reduce, that the effect can combine, in which case you're into homebrew territory. But you'll more then likely want to look at the other possibility.

The bodice has a feature (not spell) to make the wearer larger

This is not unheard of. As mentioned in the comments, the Rune Knight has Giant't Might to make themselves Large. Since this is not a spell, the two can overlap.

In this case, you can review other similar questions:

• How do Giant's Might feature and Enlarge/Reduce spell interact?
• Does an Enlarge/Reduce spell on a druid affect the beast form if the druid Wild-Shapes?
• Is there a way to increase a creature's size category twice?

However, none of which seem to have an answer as far how to play the creature; in other words, what play effects change when you upscale a Medium creature to Huge. And probably for good reason.

If it's just for looks and not abilities, I don't see much trouble.

If it makes a difference to strength, height, weight, weapon damage, radius, attack of opportunity, and other mechanics, you are going to have problems. And a lot of opinions.

Look at how to compute damage:

• Going from Medium to Large via Enlarge you add 1d4 to damage.
• Going from Medium to Large via Giant's Might you add 1d6 to damage (and only once on each of the fighter's turns).

Which means the rules aren't even consistent about increasing one size scale. You're trying to change two size scales (going from Medium to Large to Huge). So do you add 1d4 + 1d6, 2d4, 2d6, 1d8, or some other dice formula?

Now consider that everything you wear will also increase in size. So that two-foot radius shield is now closer to eight-foot (2 * 2 * 2), but still only weighs 6 pounds? That shield is now a sail meaning you could be blown over with a light breeze. You're 15-20 feet tall, but only 200 pounds. Picture a tree with no roots.

I'm not saying don't allow these things to interact (as there are combinations that can work), but and someone asked, Would it be balanced to allow Enlarge/Reduce to double its effect when upcast?, and the answers have a number of different opinions. So if you can avoid including any mechanical changes, merely cosmetic.

One more thing to consider... movement

One of the things I thought about was tanking. At 15x15, they could block most doors, passages, corridors, etc. Then all they need to do is Dodge every round and none shall pass. And per the rule of movement in combat:

You can move through a nonhostile creature's space... Whether a creature is a friend or an enemy, you can't willingly end your move in its space.

So the rest of the party could be on the far side of the tank, walk 10', do a ranged attack, then walk back 10' and be behind cover. No Attack of Opportunity. Complete cheese. But then I read the full entry...

1. Remember that another creature's space is difficult terrain for you.

So if an ally walked 10' through the tank's space, that's actually 20' of movement. Most creatures wouldn't be able to walk out.

2. Whether a creature is a friend or an enemy, you can't willingly end your move in its space.

So you're ally would end up in the same space causing issues (DM fiat on how that works).

3. In contrast, you can move through a hostile creature's space only if the creature is at least two sizes larger or smaller than you.

By becoming Huge, you are no longer a road block. Medium sized enemies and smaller can pass through just as easily as allies. Spend 30' of movement to go under your 15 sq ft cube and it's like you didn't exist.

So since the bad cancels out the good, I don't think it's unfair, but it may make the wearer think twice about growing twice.

Answer 2

As you have worded it, yes, you can combine these effects.

@MivaScott is correct that you cannot be under multiple instances of any particular named effect. So, if the bodice in question allows the wearer to cast Enlarge/Reduce, then they could not stack the effects of an Enlarge/Reduce spell cast by another character.

However, you can have a single attribute affected by more than one source. For instance, if you were affected by second level exhaustion, your speed would be halved. If someone then cast Slow on you, then your speed would be halved again, leaving you with about a quarter of your base speed.

You stated in your question that the bodice allows the wearer "to increase her size (as per the Enlarge/Reduce...". That sounds to me like it is a size-affecting effect distinct from the Enlarge/Reduce spell. So, it is allowed to have the bodice increase the character's size category from medium to large, then have Enlarge/Reduce cast on her to increase from large to huge.

Now: is this a good idea? 5e is not generally expecting a player character to be huge, so beware of mechanisms that simply do not apply to huge characters. @MivaScott again gives good examples here.

However, if you dont mind (and you think your players won't mind) the huge size potentially becoming a defining characteristic of this character, then go for it. The things I'd watch out for are: 1) a huge player may make some encounters, especially in published adventures, trivially easy, 2) whoever is casting Enlarge/Reduce may be annoyed if they are expected to always save a spell slot for that spell, rather than preparing something that makes their character cooler, 3) other martial characters may feel left out if the enlarged character is doing a fair amount of extra damage, and is able to form a front line all by themselves / taking up all the room next to enemies.

Answer 3

Whether you can combine the bodice with Enlarge/Reduce depends on the specific wording.

As for the benefits, they aren't much.

From the rules on Combining Magical Effects (Player's Handbook pg. 205):

The effects of the same spell cast multiple times don't combine...

So, if the bodice says some variation of you casting Enlarge/Reduce, then it doesn't combine with the spell.

If, however, the bodice doesn't say cast, but instead simply talks of gaining an effect, it might combine:

Many items, such as potions, bypass the casting of the spell and confer the spell's effects. (Dungeon Master's Guide pg. 141, Spells)

Different game features can affect a target at the same time. But when two or more game features have the same name, only the effects of one of them-the most potent one-apply while the durations of the effects overlap. ... Game features include spells, class features, feats, racial traits, monster abilities, and magic items. (Dungeon Master's Guide pg. 252 Combining Game Effects)

Since the bodice is an item, and Enlarge/Reduce is a spell, they are different game features.

Further, saying "gain the effect of" is one way that a rule system can convey an equal benefit while keeping word count low.

For the sake of completeness, there is one more complicating factor, this passage from Xanathar's Guide to Everything (pg. 5, Combining Different Effects:

Different game effects can affect a target at the same time. For example, two different benefits can give you a bonus to your Armor Class. But when two or more effects have the same proper name, only one of them (the most powerful one if their benefits aren't identical) applies while the durations of the effects overlap.

Taking everything above into account, here are three example wordings:

1. You can cast enlarge/reduce, enlarge form only. - If the bodice uses this form, it cannot combine with the spell.
2. You gain the "enlarge" effect of the enlarge/reduce spell. - If this wording, it would combine as per the Dungeon Master's Guide, but maybe not as per Xanathar's Guide to Everything. You would have to adjudicate.
3. You increase in size as if you had cast enlarge/reduce. - If this wording, it would combine, as it is clearly only referential to the spell.

So, whether the bodice combines with the spell will depend on which of the 3 above wordings is closest to its description.

Personally, unless it explicitly says the spell is cast, I would rule that it can combine.

The benefits of such a combination would be +1d4 damage (for a total of +2d4), advantage on Strength checks and saving throws, and a greater vertical reach.

Honestly, the detriments are more impactful: occupying more spaces, which means more enemies can reach the PC; weighing 64 times as much, which would limit where the PC can stand; much greater difficulty in finding cover.

Overall, I would say it is possible to combine the item with the spell, but the negatives would outweigh the positives under most circumstances.