D&D 5E Touch AC in 5E

[NotAYakk]

Touch AC was dropped because "Touch attack" and "Dex save" represent basically the same thing in fiction.

 

[GMMichael]

I think touching a shield is a different question than touching the person wielding it, since the idea of a shield is to put it in the way of an attack. . .

Except... don't the rules state that just holding a magical shield grants its magical defense? That implies a significant bond between shield and wielder.

I briefly considered just giving the creature a discrete bonus or Advantage on attack rolls against armored targets, since (as @humble minion pointed out) there are a ton of different bonuses added to AC besides just armor or shields.

Advantage against medium- and heavy-armored targets, and anyone using a shield. Hardly fiddly or complicated.

The devil will be in the special cases. As it's a monster ability rather than a general mechanic, that cuts down a lot of the permutations, but there's still a few you want to think about. Mage armour? A monk's Wisdom bonus to AC? An unarmoured barbarian's Con bonus to AC? Shield of faith?

The point of Advantage is to smooth over the special cases, so I think it helps as a solution here. So...
Mage armor: unaffected, since it's neither medium nor heavy armor.
Monk bonus: same as mage armor.
Barbarian: see above.
Shield of faith: a spell, not a shield. Unaffected.

 

[Hriston]

Except... don't the rules state that just holding a magical shield grants its magical defense? That implies a significant bond between shield and wielder.

Well, the same rules state that a magical shield must be donned -- "strapped to the arm" -- to use its magical properties, so there seems to be a fair amount of ambiguity there.

 

[NotAYakk]

Yes, dex save. Also makes sure you don't directly compare it to unarmored AC. In 4e I thought it was inelegant when your reflex defense (which was effectively touch AC) was higher than your actual Armor.

So, neat math is that a save of +X is roughly as hard to "hit" as an AC of 14+X.

But the lack of direct comparison does help, as noted.

 

[toucanbuzz]

I've thought about it only in the context of explaining why crossbows were so deadly at short range, that essentially armor was useless against them due to the sheer power, and firearms built on that. DEX already gets way too many goodies, so brainstorming perhaps such weapons at the close range would attack "Touch AC" of 8 (or 10) + Proficiency Bonus, and have "exploding dice" damage (roll X on the die, roll another and add that damage, if you roll X again, repeat).

 

[Quartz]

I'm playing around with the idea of adding back the Touch AC mechanic from 3.X Edition.

Please don't. KISS applies and you're penalising those who wear armour. Variable ACs were one of the worst things about 3E.

 

[The Crimson Binome]

If you look at the situations where 3E touch attacks were translated into 5E, they either turn it into Advantage on the attack roll, or they make it a Dex save. Re-calculating AC is off the table, as far as 5E is concerned.

While it is your game, and you're free to spend as much time as you want on it, consider why 5E took this approach in the first place. Generally speaking, a touch attack would pretty much amount to a bonus of ~5 on the attack roll, so the benefit of spending any extra effort on nailing the exact modifier is pretty minimal. If you really want a situation where the rogue is at +10 compared to the paladin, then that's what Dexterity saves are for.

I can say that, from a player perspective, I would be somewhat annoyed with a DM who introduced a new statistic into the game I was playing. It's not something I could ever anticipate or plan for, which kinda defeats the point of planning for anything in the first place. You might as well be making your attacks against my History bonus, as far as I'm concerned.

 

[jmartkdr2]

Isn't that a feature of touch attacks, not a problem?

It's a feature form the attacker's point of view, but kinda crappy if the player built their character to be really tough and the monster just sidesteps that by ignoring all the established defensive options.

I'd go with dex saves myself - that's how disintegrate works already and the player knew about those ahead of time.

 

[CleverNickName]

Please don't. KISS applies and you're penalising those who wear armour. Variable ACs were one of the worst things about 3E.

I promise not to make anyone else use my house rules.

I'm okay with "penalizing those who wear armor" in this situation. This is just one encounter, not a global change to the rules. I want to make the players think a little outside the box, and try some new tactics for a change. But who knows? If I like the way the encounter feels, I might add this ability to other monsters in the game. If I don't, I'll never use it again.

Here's the version I'm gonna run with. Thanks for your input, everyone! I'll let you know how it shakes out.

Touch Attack. The <monster> makes two claw attacks at +10 to hit. Against creatures wearing armor or using a shield, these attacks are made at +12. Against creatures both wearing armor and using a shield, these attacks are made at +14. On a hit, the creature takes <damage> and must make a <DC> Dex save if it is wearing armor or using a shield. On a failed save, the target's armor or shield <effect>. If the target is using both armor and a shield, the target chooses which item is affected.​

 

[NotAYakk]

I promise not to make anyone else use my house rules.

I'm okay with "penalizing those who wear armor" in this situation. This is just one encounter, not a global change to the rules. I want to make the players think a little outside the box, and try some new tactics for a change. But who knows? If I like the way the encounter feels, I might add this ability to other monsters in the game. If I don't, I'll never use it again.

Here's the version I'm gonna run with. Thanks for your input, everyone! I'll let you know how it shakes out.

Touch Attack. The <monster> makes two claw attacks at +10 to hit. Against creatures wearing armor or using a shield, these attacks are made at +12. Against creatures both wearing armor and using a shield, these attacks are made at +14. On a hit, the creature takes <damage> and must make a <DC> Dex save if it is wearing armor or using a shield. On a failed save, the target's armor or shield <effect>. If the target is using both armor and a shield, the target chooses which item is affected.​

Touch Attack. The monster selects two targets (including the same one twice) within 5 feet. They must make a DC 18 dexterity saving throw or suffer X. In addition, if they are wearing armor or a shield, they must pick one to suffer Y.

I mean, the same fiction (attempting to touch someone with an effect that ignores the defense of armor), established mechanics, twice as fast to evaluate.