Evasion 5e dnd for rogue
At the 7th level, rogues gain the Evasion 5e feature. Beginning at 7th level, you can nimbly dodge out of the way of specific area effects, such as a red dragon’s fiery breath or an Ice Storm spell. When you are subjected to the effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no harm if you succeed on the saving throw and only half damage if you fail.
The first sentence of Evasion is almost certainly “flavor text” with no mechanical effect. Several monsters are listed with an Evasion trait whose text is nearly identical to the second sentence of the rogue’s and monk’s Evasion traits. For example, the assassin and the master thief, both based loosely on rogues of 12th and 13th level respectively, have this ability:
If the assassin is subjected to the effect that allows it to make a Dexterity saving throw to take only half damage, the killer instead takes no damage if it succeeds on the saving throw and only half damage if it fails.
Rogue 5e Evasion
While this ability is nearly identical to the 2nd sentence of Rogue’s Evasion, it omits the first sentence entirely. Regardless, even for monsters based loosely on PC classes, there is no requirement for the mechanics to match up exactly. However, with the publication of Acquisitions Incorporated, the monster list now also includes a stat block for Viari. We know for sure that this monster stat block is based on the PC version of Viari’s stats: a 10th level thief rogue, it would seem. And Viari’s Evasion feature also omits the first sentence:
If Viari is subjected to the effect that allows him to make a Dexterity saving throw to take only half damage, he instead takes no damage if he succeeds on the saving throw and only half damage if he fails. He can’t use this trait if he’s incapacitated.
Given that Viari is explicitly based on a PC with the Rogue’s Evasion feature removing a sentence from that feature for the non-PC stat block seems quite odd if this sentence is indeed meant to have mechanical implications. However, if we instead conclude that this sentence is purely flavor text, its removal makes perfect sense in a context where flavor text is extraneous, such as a monster’s stat block.
From this, I conclude that in the Rogue’s Evasion 5e feature (and by extension the monk’s), the first sentence is treated as dispensable flavor text with no automatic import. That, in turn, means that the Evasion feature of the Rogue and monk works identically to the monsters’ Evasion feature: an area of effect is not required.
Does 5e Evasion need an area of effect & Dexterity save in dnd?
Evasion requires both area-of-effect and Dexterity-save-for-half.
D&D rules are meant to be parsed as plain English – one can write about a “green car” in one sentence, then continue talking about that car in subsequent sentences without the need to specify that the car is green repeatedly. The word “effects” in one sentence is implicitly referring to the same “effects” in the next; there’s no need to specify “area repeatedly.”
Furthermore, one sentence can be helpful to narrow a definition from a previous sentence. In this case, the first sentence specifies “certain area effects.” The second sentence defines what those specific effects are – effects that include a Dexterity saving throw for half damage.
Does Evasion 5e dnd work against effects that don’t target an area?
Could it have been written in a more technically precise manner? Sure1, but that isn’t licensed to selectively disregard one sentence in favor of another when there is an accurate reading that takes both sentences into account.
There’s nothing beyond the text you’ve already quoted on Evasion, which indicates it only works on Dexterity-based area effects that allow a save-for-half. The examples provided are illustrative, not exclusive-and-complete.
What’s an Area of Effect?
The spell or effect’s description will indicate if it’s an area effect, in most cases using one of several defined shapes – line, cone, cube, SphereSphere, or cylinder. Enervation, Disintegrate, and Immolate may have Dexterity saves, but they are not both area effects and save-for-half, so Evasion doesn’t help. Chain Lightning hits multiple targets, but it can skip over people in between, so it’s not an area effect either.
Room for Debate
Flaming SphereSphere is a bit of an edge case. Evasion definitely wouldn’t help against the ram because it’s not an area effect. The end-of-turn burn is debatable and could be argued either way; it’d be a DM call. I’d never call it RAW, but this DM would allow Evasion to work against the end-of-turn burn, as I see Evasion being the Rogue easily and quickly finding an exact position to avoid the brunt of an area spell, and would count skirting the edges of Flaming Sphere’s heat as doing just that.
Does Evasion allow half damage when unconscious?
Yes. RAW, Evasion means a character only takes half damage, even when unconscious.
The relevant part of the 5e Evasion text that you’ve quoted says:
When you are subjected to the effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no harm if you succeed on the saving throw and only half damage if you fail. (SRD p. 28, 38, 40)
The Unconscious condition states:
An unconscious creature is incapacitated (SRD p. 359)
That means they:
can’t take actions or reactions. (SRD p. 358)
However, nothing in the ability Evasion says that it requires an action or reaction for use. So Evasion is an ‘always on’ ability.
The triggering condition is being ‘subjected to the effect that allows you to make a Dexterity saving throw,’ not whether or not the creature can make that throw due to other conditions already affecting them. If this caveat was intended, it should be explicit (in 5e ‘there aren’t any secret rules’).
However, also while Unconscious:
The creature automatically fails Strength and Dexterity saving throws. (SRD p. 359)
So, while a character is unconscious, they’ll automatically fail Dexterity saving throws, but thanks to Evasion, they’ll still only take half damage.
If this ruling seems odd to you (and I can see why it might), then you are, of course, always welcome to rule otherwise in your own game.
But mitigating circumstances mean that this isn’t as bad as it seems.
Firstly, when a character is already unconscious due to HP loss, they are less likely to be targeted by AOE attacks (so this will be an issue less frequently than you might imagine).
But secondly, and much more importantly (presuming that the target isn’t simply asleep or drugged and except for the ‘massive damage’ rule), how much damage you take. At the same time, unconscious doesn’t usually matter at all.
Death saving throw
What matters is how many 5e death saves you’ve failed.
If you take any damage while you have 0 hit points, you suffer a death-saving throw failure. (SRD p. 98)
Taking any damage will always equate to one failed death save, whether or not it’s halved. (Critical hits would cause two failed death saves, but non-attacks such as spells and other abilities that force you to make a Dexterity save can’t be critical hits anyway.)
It works against all “Dex save for half damage” effects
Despite the first sentence in the paragraph mentioning “certain area effects,” I believe the second part is more critical:
When you are subjected to the effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no harm if you succeed on the saving throw and only half damage if you fail.
That does not mention only spells that have a specified area. There is an argument that the 5th edition has no ‘fluff text’; hence the 1st sentence still applies. But it does have the concept that rules should be like plain English, and I believe this is a case where an accurate English word (‘area’) unfortunately coincides with a rules term used in spell descriptions.
Dexterity saving throw
Another way of looking at this is that all spells that require a Dexterity saving throw have some area. Otherwise, there would be nothing to attempt to dodge away from (which is precisely what a Dex save represents). It’s just that sometimes, for spells such as Sacred Flame or Immolation, that area covers only a single individual creature, and hence there is no requirement to have an ‘Area’ stated in the spell description.