D&D 5E Touch AC in 5E

[Lanefan]

The problem with Touch AC is the notion that your level 12 Fighter with a Sword in his hand which he is exceptionally good at but with Dex 10 (Cos Heavy Armour) can't actually defend himself with any competence.

That's not the problem, it's the point!

The whole idea of touch AC is that sometimes armour just doesn't help very much: you're going to get hit anyway, so best to just attack all-out. As a pleasant side effect, a fight against creatures using touch attacks gives some usually-non-melee characters a chance to do some real fighting.

I'd been using a variant of touch AC for years without realizing it, before 3e formalized it.

 

[Lanefan]

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

I thought it was one of 3e's better ideas.

It only makes sense that different armour and-or defenses are going to apply in different situations.

 

[Don Durito]

That's not the problem, it's the point!

The whole idea of touch AC is that sometimes armour just doesn't help very much: you're going to get hit anyway, so best to just attack all-out. As a pleasant side effect, a fight against creatures using touch attacks gives some usually-non-melee characters a chance to do some real fighting.

I'd been using a variant of touch AC for years without realizing it, before 3e formalized it.

But what about your skill? How do you make sense of this? Is the 20th Level Fighter no better at putting his sword in the way of someone trying to touch him than the 0 level peasant?

By and large the fact that D&D doesn't model the skill with weapons doesn't matter much because it gets hidden under normal play by AC. But it becomes very stark if you take the armour off the Heavily Armoured character. It produces really nonsensical results.

 

[Hriston]

Is the 20th Level Fighter no better at putting his sword in the way of someone trying to touch him than the 0 level peasant?

Yes, he has more hit points.

 

[Bacon Bits]

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

There's a reason this design was eliminated from the game. It lets you circumvent the basic defense statistic of the game with a "defense" that never scales. It's a bad design. It just punishes characters who make choices and investments for heavy armor and shields when the game already overly favors high Dex. Touch AC is the Nilbog of combat defense design.

The closest acceptable approximation, IMO, is Shocking Grasp, which grants advantage against metal armor. That I think is fine.

 

[Lanefan]

But what about your skill? How do you make sense of this? Is the 20th Level Fighter no better at putting his sword in the way of someone trying to touch him than the 0 level peasant?

Because D&D doesn't really use weapons as defense mechanisms, the answer here is essentially no: provided they each have the same Dex score the high-level Fighter (the high-level anyone, for all that) and the peasant are the same. The difference is that the high-level Fighter probably has access to various magical things that can help her touch AC (e.g. devices of Protection) and-or provide her with better means of escape (e.g. devices of levitation or flight).

Also, the high-level Fighter is going to be able to chop up whatever's initiating those touch attacks far faster than any peasant could.

By and large the fact that D&D doesn't model the skill with weapons doesn't matter much because it gets hidden under normal play by AC. But it becomes very stark if you take the armour off the Heavily Armoured character. It produces really nonsensical results.

Nonsensical only if you think that high level provides a buffer against everything.