D&D 5E rules for attacking with a shield?

[Plaguescarred]

Improvised weapon, 1d4 damage, and you're probably not proficient with it.

This, you can always use a shield as an improvised weapon.

 

[pepticburrito]

You can't do it. A shield is not in any way to be construed as a weapon. Get that thought out of your head and pretend you never had it!

Take a look at Lizardfolk. Page 204 Monster Manual and/or page 35 Basic DMG. They have something really interesting in their gear, a spiked shield.

Spiked Shield. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage.

Judging from the attack bonus and damage, it's a Strength based weapon and a shield at the same time. I would say, it's kind of impossible to get that thought out of ones head, because an shield that you can attack with exists in 5e.

 

[ccooke]

This, you can always use a shield as an improvised weapon.

It's also worth noting that there is nothing in the 5e rules that says that you lose the shield's AC bonus if you attack with it.

If you have a shield, you can attack with it as an improvised weapon (with disadvantage and without including your proficiency), doing 1d4+ Strength modifier damage on a hit.
If you have a shield and proficiency with improvised weapons (for instance, through the Tavern Brawler feat), you can shield bash without disadvantage (and include your proficiency)

There is an interesting synergy between Tavern Brawer and Shield Mastery - with both, you can attack with the shield, then take a bonus to shove with it or (if you hit) a bonus to grapple. I can see a character with a shield and empty hand using both of those feats to interesting effect. Maybe a melee caster such as a valour bard, with a spiked shield (I think many GMs would allow that to be made, and do d6 piercing damage) and Expertise with Athletics...

... Damn, I think I need to stat that character up at some point.

 

[Henrix]

The Shield Mastery feat gives you a bonus action to Shove with your shield, not attack.

Thank you for explaining how Shield Mastery works.
In what way is shoving with your shield not a bash with it?

Suddenly fighters with shields prefer the Two weapon style in order to add their ability modifier to damage with the shield.
Shield masters get to pick whether they deal damage or shove the opponent as their bonus action.

I can choose a light weapon dealing 1d6, or a shield dealing 1d4 as well as AC, etc, if I take a feat, in my off hand.

I think I'll pass that house rule, but to each her own.

 

[Henrix]

It's also worth noting that there is nothing in the 5e rules that says that you lose the shield's AC bonus if you attack with it..

There is nothing in the rules that say a shield is a light weapon. In fact it is quite contra intuitive. Thus you can normally choose whether you want to use it or your main hand weapon to attack with, but not both.

There's nothing in the rules that say you can get AC from an improvised (or other) weapon you use to attack with.

 

[ccooke]

Thank you for explaining how Shield Mastery works.
In what way is shoving with your shield not a bash with it?

Because a shield bash involves an attack roll and potential damage. Shield Mastery allows you, when you use the Attack action, to use a bonus action to Shove using your shield. Shove is, technically, a thing that can be done using the Attack action that is not an attack - you forego the attack roll and possible damage in exchange for contesting your Strength(Athletics) against the target's Strength(Athletics) or Dexterity(Acrobatics) and, if you win, you can knock the target prone or push them 5'.

Suddenly fighters with shields prefer the Two weapon style in order to add their ability modifier to damage with the shield.

Certainly some will, but they will need a total of two feats to do it:
Dual Wielder (to allow them to use Two Weapon Fighting with weapons that are not light - a shield is not light)
Tavern Brawler (to allow them proficiency with the shield as an improvised weapon. Otherwise they would be attacking with disadvantage every time and not adding their proficiency bonus)

Shield masters get to pick whether they deal damage or shove the opponent as their bonus action.

No, Shield Masters who are also have the Tavern Brawler and Dual Wielder feats get that choice.

I can choose a light weapon dealing 1d6, or a shield dealing 1d4 as well as AC, etc, if I take a feat, in my off hand.

As above, no. You need two feats to make it work.

I think I'll pass that house rule, but to each her own.

It's not a house rule, it's the RAW. Now, you can house rule that this is not possible in your game and that's fine. Personally, I think two feats and a number of class options sunk into making a mechanic viable is enough of a price to balance it. It's reasonable enough to be totally viable to build a character towards this path, expensive enough to be rare and, while it's a nice effect, it's not so powerful that every character is going to want to do it. It makes an interesting flavourful choice to build a character around, while being mechanically viable.

At this point, I'm just going to go on to what's become my standard refrain of taking this as an example of why 5e is such a great, flexible system. I'll spare you the details

 

[pepticburrito]

The Shield Mastery feat gives you a bonus action to Shove with your shield, not attack.

So, what happens when a player with that feat uses a spiked shield he took of a Lizardfolk to "shove" somebody? A Stength based spiked shield is in the Lizardfolk stat block.

 

[ccooke]

There is nothing in the rules that say a shield is a light weapon. In fact it is quite contra intuitive. Thus you can normally choose whether you want to use it or your main hand weapon to attack with, but not both.

At no point did anyone I've seen claim that a shield is light. It isn't.
I'm not sure what you're trying to refute there. Am I missing something?

Edited to add: Ah, I see where the suggestion was. That wasn't me, though. I completely agree with you in that a shield should not be light.

There's nothing in the rules that say you can get AC from an improvised (or other) weapon you use to attack with.

Actually, there is.

One of the Ur-Rules of 5e is that "specific beats general".
If you use a Shield, you get to add +2 to your AC if you are proficient with them. That is a specific that overrides the general case that objects you hold do not add to your AC.
There is no rule, anywhere, that says you lose the +2 to your AC under any circumstances other than no longer using the shield. That would be a specific overriding the more general "shields give you +2 to AC if proficient" rule but, as I said, it does not exist.

You can attack with any object you can hold in one or two hands as an improvised weapon. No class automatically gets proficiency with improvised weapons, and therefore anyone attacking with a shield will be doing so with disadvantage, and without their proficiency bonus.

 

[ccooke]

So, what happens when a player with that feat uses a spiked shield he took of a Lizardfolk to "shove" somebody? A Stength based spiked shield is in the Lizardfolk stat block.

Up to the GM to make a ruling. At the very least, though, they aren't going to be proficient with it.
My ruling would be that the bonus action to shove remains just that. A bonus action to shove. Otherwise the spiked shield is just an improvised weapon that deals d6 piercing damage and gives you +2 to AC.

 

[pepticburrito]

At the very least, though, they aren't going to be proficient with it.

Fighters are proficient in all armor and all shields. They are also proficient in the only two existing categories of weapons.

Why would a Fighter not be proficient in a Spiked Shield that he took of a Lizardfolks body?