D&D 5E (2014) The mathematics of Shield Mastery vs the -5/+10 feats

[Quartz]

The idea behind the Shield Master feat is that you bash and hopefully get advantage on your attacks, thereby hitting more often and doing more damage. The idea behind the -5/+10 feats is that you hit less often but do more damage when you do hit. How does the maths compare? How often does Shield Master actually give you advantage?

 

[Yunru]

A tricky question.
You see, pushing prone is nowhere near as... stable, as -5/+10.
With two opposed d20s, you've up to 19 points difference just from the roll. But you've also the difference in stats, and the difference in proficiency and expertise (which also varies).

IMO shoving should of never been an opposed check, but since it is and I failed maths despite being considered a prodigy because of statistics, all I can give you is an "eh."

Edit: To emphasis the wierdness of having it be an opposed check: If we assume a level 17+ character with 20 Strength and Expertise in Athletics is shoving a character with 10 Strength and no proficiency, there's a 3/200 chance of failure. It doesn't sound a lot, but this is a highest tier character, specialised into shoving, failing to shove a civilian. There's still a 3/400 chance of failure against a civilian defective in Strength (-1 modifier).

 

[Quartz]

A tricky question.

Hence my question! I'm sort of vaguely envisioning the answer involving a 3D graph involving the relative strengths as well as the ACs. I think the d20 vs d20 is actually irrelevant in the long run as both will average out so you're left with Str Mod + Proficiency Bonus. vs Str Mod or Dex Mod + possible Proficiency Bonus.

And then there's Guidance, Inspiration, Expertise, and so on to consider...

 

[Krachek]

A dancing shield to prone your opponent first would be the best combo.
Two allies with shield mastery should get you fair chance to have advantage with GWM.

 

[Blue]

The idea behind the Shield Master feat is that you bash and hopefully get advantage on your attacks, thereby hitting more often and doing more damage.

This is incorrect. You just described something that is not allowed. The current ruling (and it's flip-flopped a few times) is that the bonus action has to take place AFTER the triggering action.

So your attacks go off, then you have a chance to knock prone. Sometimes between when you went and when you go again they get their action, which they can use to get up.

Now, it can add to your allies being able to hit more, at least the ones that go between your action and when the target gets up.

If it was correct (like it was in the past), you need to not only see the bonus it gives you, but also the bonus it gives your allies. That can be pretty extreme such as in a solo fight, but it's very context dependent.

 

[Quartz]

A dancing shield to prone your opponent first would be the best combo.

That's beyond the scope of my original question.

 

[Quartz]

This is incorrect. You just described something that is not allowed. The current ruling (and it's flip-flopped a few times) is that the bonus action has to take place AFTER the triggering action.

My game, my rules. I choose the - to me - sensible ruling.

 

[Krachek]

That's beyond the scope of my original question.

I accept the objection,
To answer more directly.
The -5/+10 is the master piece of all optimizing combo and guide.
The shield mastery is a good or very good feat depending on ruling of the bonus action timing.
Making prone is situational, you may also have advantage from other source, but the damage bonus is unique and always available.

 

[Blue]

My game, my rules. I choose the - to me - sensible ruling.

There was no indication in the original post that you were houseruling or were aware of the change, since it had flip-flopped a few months back. I was trying to be helpful pointing out what the current rules are. You may want to put your house rule in your OP so others know the context you are asking.

 

[Charlaquin]

Man, Shield Mastery is a hot topic lately