D&D 5E Unarmored Defense and Surprise

[canucksaram]

The Barbarian and the Monk both have Unarmored Defense. The inclusion of DEX in the formula to calculate Unarmored Defense strongly implies to me that the word "defense" is meant in the active sense, as in "I am taking steps to evade an attack that I am aware of."

Were a character with Unarmored Defense to be the subject of a surprise attack, would their AC still benefit from the class feature?

I have a player that says "Yes," while my own instinct is to say, "No." It brings to mind the idea of being flat-footed, from previous editions of the game.

Unarmored Defense is not the same as Natural Armor. Its very name implies to me that the beneficiary of the class feature is defending him- or herself.

 

[pukunui]

Your player is correct. There is no "flat-footed" rule in 5e. In situations where that may have come up in previous editions, the 5e rules grant the attacker advantage instead.

 

[Flamestrike]

Were a character with Unarmored Defense to be the subject of a surprise attack, would their AC still benefit from the class feature?

They most certainly do.

If their attacker is hidden, then he makes his attack with advantage. If he attacks from surprise, he gets a chance to attack twice before his opponent can do anything about it.

Both are significant penalties. No need to do any more than this.

 

[Leatherhead]

Unarmored Defense is not the same as Natural Armor. Its very name implies to me that the beneficiary of the class feature is defending him- or herself.

Ignoring that Barbarians are immune to surprise anyway, they use CON as their stat boost. This kind of implies it is sort of like natural armor, seeing as how they are using the physical structure of their body in order to avoid damage. And don't forget creatures with natural armor, like say Dragon-Sorcerers, also add their DEX to their AC. As for monks? Ignoring Unarmored Defense is too much math for a minuscule chance that you will somehow catch a Monk (who pump up their WIS scores as a matter of course) off guard. Also, Monks aren't considered overly powerful to begin with.

 

[thorgrit]

If you can think of unarmored defense being mostly active, you can think of armor and shields the same way too. Armor doesn't encase perfectly, it has joints, weak points, and exposed areas. An armor-wearer would probably use that to their advantage, dodging, turning, so that close attacks glance off instead of hitting a vital spot. Especially true for shield-users. If attacked completely unaware, advantage to the attack roll works equally well for an armored target vs a dodgey/dex target.

 

[Caliburn101]

WoTC decided to front load the resolution of how much extra bang for your buck you get from achieving surprise by giving the acting character advantage. Recalculating the defensive target number was always fiddly and time consuming and had to take into account the kind of granularity in the details of AC that were never envisioned when this mechanic was invented.

So the current 5E system is more than suitable, and no more odd than the HP or healing systems in place.

 

[Plaguescarred]

Were a character with Unarmored Defense to be the subject of a surprise attack, would their AC still benefit from the class feature?

Yes.

As funny as it sound, a creature retain his AC bonus (including Dexterity) even while unconscious! Like pukuni said 5E instead grant advantage on the attack roll against you.

 

[canucksaram]

Thanks for the input, folks.

I'm going with my gut, nonetheless: Rulings, not rules, and as such AC derived from Unarmored Defense (and ability scores/similar sources) is dependent upon one's ability to use their reaction as a part of self-defense.

Natural Armor and worn armor do not require one to use their reaction as a part of self-defense.

Advantage still applies to surprise attacks.

This goes for the goose as well as the gander.

Official 5E may have done away with flat-footed but that was a mistake, in my view.

 

[Yunru]

Thanks for the input, folks.

I'm going with my gut, nonetheless: Rulings, not rules, and as such AC derived from Unarmored Defense (and ability scores/similar sources) is dependent upon one's ability to use their reaction as a part of self-defense.

Natural Armor and worn armor do not require one to use their reaction as a part of self-defense.

Advantage still applies to surprise attacks.

This goes for the goose as well as the gander.

Official 5E may have done away with flat-footed but that was a mistake, in my view.

Expect to see player complaint then, as you're taking away features that are intended to be always on for balance purposes (and which should only be done before character creation).
Also expect to see no more Monks in your group.

 

[canucksaram]

Expect to see player complaint then, as you're taking away features that are intended to be always on for balance purposes (and which should only be done before character creation).
Also expect to see no more Monks in your group.

Fine by me. If a player wants to be a rules pedant rather than a flexible player, well...that's a style of game play I can do without.

Someone posted that a DEX bonus would apply to a sleeping person's AC, and with no slight intended to him or her, that's just silly. I would simply rule an autohit in that case--no need to even make a die roll, advantaged or not.

The rules are a guide to how things work in most situations, most of the time. Common sense has a place, too, thus the need for DM adjudication. Rulings, not rules...suspension of disbelief, not total disregard for disbelief.