Is it against RAW to allow an Enlarged/Oversized net to restrain a Huge creature?

Question

A net's rules specify that it has no effect on a Huge (or Gargantuan) creature (probably because the net would be too small to bother such a creature).

However, when targeted by the Enlarge effect of an Enlarge/Reduce spell, a net grows twice larger, and thus could logically be used to restrain larger creatures. Also, there's a DMG variant for oversized weapons, which only speaks about damage increase and attack disadvantage for Medium creatures, but as the equivalent of "damage" for nets is the restrained condition, it could be logical to think that the gained effect from an oversized net over a regular one is the ability to target larger creatures.

My question is : is it against the rules as written to allow an Enlarged/Oversized net to restrain a Huge creature ?

Argument in favor of a yes : The rules on nets don't mention anything about the net's size, and considering the specific-beats-general rule, nets could be considered as more specific than oversized/enlarged objects.

Answer 1

There is no official ruling, but allowing it does not seem to be unbalanced.

As you mentioned in your question, there are no explicit rules stating how the Net interacts with being Oversized (made for something larger than Medium), and I cannot find any official statements from Sage Advice addressing it. Therefore, this is purely up to the DM.

But, for the sake of looking into this a little more closely...

Prior Edition Precedent

Per the 3.5E SRD:

A net is useful only against creatures within one size category of you.

So, in 3.5E, if you were a Medium creature, then a Net sized for your use would work on Small, Medium, and Large creatures, and nothing else. Therefore, if you were Large and using a net made for a Large creature's use, then it would work on Medium, Large, and Huge creatures. So, per the 3.5E rules, an oversized net (made for a Large creature) would work on a Huge creature.

So, there is established D&D precedent for a Net targeting different sized creatures based on the size wielder it is made for.

Thematic Analysis

While there is no explicit statement saying this, logically it follows that the 3.5E ruling works for this reason: too small of a creature would fit through the gaps of the net and not be restrained, while the net wouldn't be big enough to entangle a creature that was too large (you might wrap it around one leg...but that's not going to accomplish much).

Mechanical Analysis

A weapon that can apply the Restrained status is certainly useful. Restrained is a fairly nasty condition. However, a net is quite easy to get out of...for most creatures, it just eats up an attack or an action, and there are lots of things that do that.

Additionally, if we take a look at Grappling...

The target of your grapple must be no more than one size larger than you and must be within your reach.

So, a Medium Creature cannot grapple a Huge creature, same as they can't hit them with a Net. But an Large Creature can grapple a Huge creature. So, even within 5E, there's precedent for player-applied conditions that only work on certain size creatures scaling with your size.

Conclusion

Based on the 3.5E Precedent, and the way Grappling already behaves, I see no reason why this would be unbalanced, and it makes sense from a thematic perspective. If you are still uncertain and want to add a drawback to this, then adopt the downside provided in 3.5E: As you increase the size of the net, it stops being able to restrain creatures that are too small.

Answer 2

DM's Call, but it seems OK

This isn't against RAW because RAW doesn't address this situation. As a result, the DM would make a ruling. Here's what I'd rule and why:

Previously you were asking about the balance of the proposed idea and although you stated you were asking about Rules as Interpreted, I think your underlying question is still inherently about the balance of the proposed idea.

In general, whenever I need to gauge if something is balanced or broken, I ask whether or not this would become my default preference for this scenario. If the answer is 'yes' then it's probably broken.

I am going to take the example towards an extreme and say that the party is fighting an Empyrean, (CR23 Huge Celestial). It has a melee bludgeoning attack and a ranged bolt attack, essentially nothing that can destroy a net, so were it netted it would need to expend it's Action to do so. This is a legendary creature as well, but legendary actions are tightly controlled in what they can do with them.

From a RAW perspective, the net Restrains a target (0 speed, Advantage to attackers, Disadvantage to the netted creature). It's effects are removed when it's destroyed from either 5 slashing damage or the trapped creature making a DC10 Strength check to burst it using their Action.

There's a cost associated with what you're proposing. First an attack roll needs to be made with Disadvantage because the weapon is oversized, but it was already at Disadvantage because net's have a range of 5' and thus need to be thrown when within 5' of the target (or from 15' out and a long distance throw is required). In short, the oversized weapon rules provide no additional penalty beyond the already built-in penalty.

The second cost is the expenditure of a spell slot and concentration with it. This cost of this in the action economy depends on how the spell is cast.

The third cost is the attack roll itself. The net is a martial weapon and although Disadvantage applies, a 17th level character with a maxed Str/Dex stat has a +11 to hit. Versus the Empyrean's 22 AC, the Disadvantage is a significant issue. It's also worth noting that this attack roll consumes an entire Action, you cannot make followup or iterative attacks.

So for the cost of 2 Actions, 1 spell slot, concentration, and a good roll you can inflict the Restrained condition on an Empyrean and force them to spend their Action to recover. Furthermore, once the net is broken, that spell no longer provides any ongoing benefit.

More or less, this is a teamwork attack that requires coordination, the notable expenditure of resources, and a little luck to work for a short-term (but potentially significant) benefit.

I would allow it, but I would state that the caster must maintain concentration.

Answer 3

It could be imbalanced due to action economy.

Consider the setup. RAW seems to prohibit nets against huge creatures rather specifically. This is partially because low to mid level characters will generally struggle with huge creatures, they cannot flank it, nor trip it or knock it down.

In the case of the entire party versus one monster, bosses usually struggle, but huge and larger creatures can sometimes get away with it for a while due to its invulnerability to most common forms of incapacitation. The action economy is tolerable to the one monster and his action disadvantage because he can continue to tank and threaten every turn even as the party swarms it. One character with a net launcher could upset this balance and waste the monsters' precious actions with relative ease.

Now, once the party is such a high level that they're fighting an entire squad of Cloud Giants at once, it seems an unimportant distinction. As the GM at that point, I'd probably say sure, go ahead with the net launcher. After all, the rules say that a "dropped" item returns to its normal size, it doesn't say anything about a thrown net you're still hanging onto.