Does the rule on falling damage only apply to Small and larger creatures?

Question

Does the rule on falling damage (1d6 damage for every 10 feet fallen) only apply to Small and larger creatures?

Suppose flying insects with 1 hit point attack the party, and a caster casts sleep into the air where they are flying 10 feet above. Should they take 1d6 falling damage?

This seems ridiculous for Tiny-sized creatures/insects who are designed to be able to withstand falls due to their exoskeleton and light body weight. If they do take damage, then should they immediately wake up from the sleep when they hit the ground?

Answer 1

RAW, insect-sized creatures take the same falling damage as all others

In the monster manual, I can find stats for exactly one creature with a similar size to an insect: the spider. The stat block for the spider makes no mention of falling damage, which means it obeys the usual rules: 1d6 bludgeoning damage for every 10 feet fallen. So, the spider's stat block gives us a precedent to show that the rules for falling damage do apply even at this size.

However, by its nature, a spider is very unlikely to ever fall, unlike a flying insect, and the monster manual doesn't give stats for any flying insects. So you are stepping into somewhat unexplored territory by home-brewing your own flying insect stats. As long as you are home-brewing the creature, you might as well say that it does not take falling damage if you think that makes sense.

Consider using a swarm instead

Alternatively, you could accept that the "physics engine" of D&D is poorly suited for modeling individual creatures of such a small size, and take an alternate approach: swarms. The monster manual gives stats for a swarm of insects. The swarm has 22 hit points (on average) and resistance to bludgeoning damage, which means that if a spell puts the swarm to sleep and it falls 10 feet, it will take a maximum of 3 damage (half of 1d6). This seems reasonable: while it's unlikely any insects would die from the fall, some of them will land badly and break a wing or something, leaving them unable to continue flying with the swarm. Hence, the swarm will be slightly diminished even if the fall wasn't fatal for any of the individual insects. So by switching from individual insects to swarms, we get a result that is much closer to what we would expect in reality while sticking to the rules as written.

Answer 2

The falling rules in the basic rules (which are also on PHB p. 183) do not specify any restrictions on what sort of creature can take fall damage:

A fall from a great height is one of the most common hazards facing an adventurer.

At the end of a fall, a creature takes 1d6 bludgeoning damage for every 10 feet it fell, to a maximum of 20d6. The creature lands prone, unless it avoids taking damage from the fall.

The additional optional rules on falling suggested in Xanathar's Guide to Everything (p. 77) modify the rate of falling and the way falling works with flying creatures:

Falling from a great height is a significant risk for adventurers and their foes. The rule given in the Player’s Handbook is simple: at the end of a fall, you take 1d6 bludgeoning damage for every 10 feet you fell, to a maximum of 20d6. You also land prone, unless you somehow avoid taking damage from the fall. Here are two optional rules that expand on that simple rule.

Rate of Falling

The rule for falling assumes that a creature immediately drops the entire distance when it falls. But what if a creature is at a high altitude when it falls, perhaps on the back of a griffon or on board an airship? Realistically, a fall from such a height can take more than a few seconds, extending past the end of the turn when the fall occurred. If you’d like high-altitude falls to be properly time-consuming, use the following optional rule.

When you fall from a great height, you instantly descend up to 500 feet. If you’re still falling on your next turn, you descend up to 500 feet at the end of that turn. This process continues until the fall ends, either because you hit the ground or the fall is otherwise halted.

Flying Creatures and Falling

A flying creature in flight falls if it is knocked prone, if its speed is reduced to 0 feet, or if it otherwise loses the ability to move, unless it can hover or it is being held aloft by magic, such as the fly spell.

If you’d like a flying creature to have a better chance of surviving a fall than a non-flying creature does, use this rule: subtract the creature’s current flying speed from the distance it fell before calculating falling damage. This rule is helpful to a flier that is knocked prone but is still conscious and has a current flying speed that is greater than 0 feet. The rule is designed to simulate the creature flapping its wings furiously or taking similar measures to slow the velocity of its fall.

If you use the rule for rate of falling in the previous section, a flying creature descends 500 feet on the turn when it falls, just as other creatures do. But if that creature starts any of its later turns still falling and is prone, it can halt the fall on its turn by spending half its flying speed to counter the prone condition (as if it were standing up in midair).

The latter (optional) rule might be relevant to your proposed scenario, if not for the fact that the sleep spell knocks the insects unconscious so it wouldn't make sense for the creatures to be able to avoid the fall damage that way anyway.

Regardless, by RAW, a fall from 10 feet up onto solid ground would kill a 1 HP unconscious creature.

Answer 3

RAW, the falling rules make no considerations for a creature's size. This seems like an instance where common sense should be applied over RAW, as the rule very starkly conflicts with reality.

If you want to make a well-defined mechanical adjustment, I might say that falling damage per 10 feet should be decreased by 1d6 for every size category the creature is below small (thus, tiny creatures take no falling damage), and increased by 1d6 for every category above medium. This isn't perfect, however, mostly due to how much the actual size of a "tiny" creature can vary.

Answer 4

Listen, I have been playing D&D since 1976, and I can tell you that the whole point of a DM is to referee situations that there is no rule for, based on the rules and what makes sense. In the beginning, we had only a basic rule set which was designed to turn life events into math. The major role of the DM is to determine "what happens when...". No matter what the rules say, if the situation doesn't seem to fit the rules, be it for or against the players, the DM's job is to help convert life into a facsimile through math.

You're right to question bugs not dying from a fall of 10 feet or so. That's not likely to happen in real life. The game could have considered an AC to modify fall damage or size as a consideration, but they cannot possibly cover everything that can happen in life. The game already has a very robust rule set; with that in mind, and your knowledge of real life, you have to decide what seems the most likely outcome.

We used to read up on physics to figure out what would make sense in some situations. I mean, the damage here is based on weight times speed. That's the real-life equation. I might think the insects wouldn't suffer any damage and would stay asleep for the duration, but that's just my interpretation.

As DM, you're the judge: you interpret the rules, and you decide what happens in the world you created. Players love a fair DM. Just be equally fair on all sides of an issue.

Answer 5

I'd say think about what the RAW are representing here. DnD isn't really meant to be a realistic game, no matter how much people haggle over how to make it that way. The best thing to do in this situation is to realize that the creatures are unconscious, unlikely to be able to do anything to mitigate fall damage. And yes, almost double the height of an average human will do some damage to a bug, especially if they don't land on their feet, even if they have an exoskeleton. Give a player some credit for thinking of an inventive way of shutting a part of the encounter you made down, and make sure to take note of what they did. Using a spell slot should be valued in this situation, especially because it's being used creatively. You never know what a player will come up with at the table, and that should be an inevitability in play.

I would also consider alternative ways of representing bugs without flying if this somehow becomes a greater issue at your table. The ability to create something amazing can often be limited by one's own unwillingness to change their tactics. Jumping is a great asset for bugs who want to attack higher up. I saw swarm mentioned in this thread, and that would mitigate the types of damage you're looking to reduce. A climbing speed would technically allow a bug to crawl onto a creature easily. There are many ways to fix this scenario, but just know if you see something like this coming, it's exceedingly less likely in practice then you think. The players first reactions to these bugs are to kill them outright or AoE them if they seem particularly bothersome, especially if they only have 1 HP. I just don't see any caster wasting a spell slot on something so easily solvable.

Answer 6

A creature as small as a spider can fall from nearly ANY height and be subject to absolutely no danger of injury.

Should take absolutely no falling damage whatsoever (if it is as small as a tiny spider)

A spider the size of your hand or larger may be subject to likelihood of injury so damage is possible and likely. - Source: Biomedical Engineer