Is my interpretation of somatic components, object interactions, and the second benefit of the War Caster feat correct?

Question

The War Caster feat (PHB, p. 170) allows a player to avoid the somatic requirement of spells when casting. However, since you can drop a weapon for free and then pick it up as a free interaction, you can completely avoid the somatic requirement while still keeping a weapon equipped at the end of your turn.

Action economy used as follows:

1. Drop weapon (free)
2. Cast somatic spell (1 Action)
3. Pick up weapon (Movement/free one-object interaction)

War Caster does have some additional perks, but considering other Feats (like Resilient) exist, War Caster seems almost useless.

I've discussed this with fellow players, and the consensus is that doing this works within the RAW, but it's also silly to abuse the action economy in this way.

Is there a consensus on whether this sort of abuse of the action economy is allowed (i.e. not simply up to the DM) when using RAW?

Answer 1

Like your fellow players, I suspect your DM may see this nifty trick as gaming the system. Your DM has broad latitude to discourage such shenanigans.

Dropping your weapon might be riskier than you suppose

The first time you drop your weapon in combat and retrieve it, maybe your enemies are surprised by this odd tactic. But the second time, they might be ready.

Grabbed objects can be picked up (by anyone!)

Going strictly by the rules, an enemy could ready an action, and then snatch away your weapon with their reaction. That’s not so good if you had a nice magic sword.

“Custom” Reactions

The rules for opportunity attacks state: “In a fight, everyone is constantly watching for enemies to drop their guard” (PH 195) and that doing so enables them to take their reaction.

Your fair-minded DM might rule that dropping a weapon is a valid trigger for a reaction, allowing an enemy to kick your weapon away.

Or a DM might rule there is a chance your weapon will be kicked in a random direction if it is dropped during melee.

Other reasons not to drop nice things

1. A dropped item becomes a valid target for spells/attacks (it's no longer protected by the worn or carried clause).
2. Dropping things while airborne, above lava, etc., is problematic

Answer 2

Dropping it

Dropping an item is not classified as a free object interaction in the books. The question and answer you link also say the same: what dropping an item in your space "costs" you is left up to the DM. But even if we assume that he lets you do it for no cost (which is reasonable):

Picking it up

You can also interact with one object or feature of the environment for free, [...] The DM might require you to use an action for any of these activities when it needs special care or when it presents an unusual obstacle. (PHB 190)

I would say that picking up an item at your feet while someone is actively fighting you in close combat needs special care. It is still left up to the DM, but ruling that picking your weapon up requires an action in a situation like this would eliminate the silliness you mention. I would certainly rule so at my table. Regardless, discuss this with your DM.

Answer 3

It's up to your DM

The free interaction in combat explicitly calls out that the DM may make additional rulings based on potential difficulty in this area.

Assuming your DM rules that dropping an item doesn't use up your free interaction with an object, then yes that specific bullet point can be mitigated for by using/abusing the action economy rules. This has the proviso, as Szega mentions in their answer, that your GM doesn't rule that picking up a weapon in combat is a special action requiring specific care.

It should also be noted that Jeremy Crawford [has posted on twitter]:

The intent is that letting go of something requires no appreciable effort. But picking it up does.

Otherwise no you cannot do this.

Is War Caster rendered useless in this case?

No

The main benefits of War Caster are the advantage on Concentration Saving Throws and the ability to cast a spell for an opportunity attack instead of a Melee attack.

The Concentration Saving Throw advantage makes it much more likely that a caster will maintain concentration after receiving 21 points or less of damage from an attack (since you only need to achieve a 10 in that situation). The tables below give the chance of success with a given ability modifier, at a particular DC (assuming a nat 20 is not an auto success).

If you are in melee with someone who has the Mage Slayer Feat, which would normally impose disadvantage on concentration checks for you, the gains from the War Caster advantage cancelling out the Mage Slayer disadvantage are equally as large.

\begin{array}{c|rrrrrrrrr} \text{DC10 check} \\ \text{(up to 21 damage)}& \rlap{\text{Ability Modifier}}\\ \text{Check Type} & -3 & -2 & -1 & 0 & 1 & 2 & 3 & 4 & 5\\ \hline \text{disadvantaged} & 16\text{%} & 20\text{%} & 25\text{%} & 30\text{%} & 36\text{%} & 42\text{%} & 49\text{%} & 56\text{%} & 64\text{%} \\ \text{regular} & 40\text{%} & 45\text{%} & 50\text{%} & 55\text{%} & 60\text{%} & 65\text{%} & 70\text{%} & 75\text{%} & 80\text{%} \\ \text{advantaged} & 64\text{%} & 70\text{%} & 75\text{%} & 80\text{%} & 84\text{%} & 88\text{%} & 91\text{%} & 94\text{%} & 96\text{%} \\ \\ \text{DC15 check} \\ \text{(30–31 damage taken)}& \rlap{\text{Ability Modifier}}\\ \text{Check Type} & -3 & -2 & -1 & 0 & 1 & 2 & 3 & 4 & 5\\ \hline \text{disadvantaged} & 2\text{%} & 4\text{%} & 6\text{%} & 9\text{%} & 12\text{%} & 16\text{%} & 20\text{%} & 25\text{%} & 30\text{%} \\ \text{regular} & 15\text{%} & 20\text{%} & 25\text{%} & 30\text{%} & 35\text{%} & 40\text{%} & 45\text{%} & 50\text{%} & 55\text{%} \\ \text{advantaged} & 28\text{%} & 36\text{%} & 44\text{%} & 51\text{%} & 58\text{%} & 64\text{%} & 70\text{%} & 75\text{%} & 80\text{%} \\ \\ \text{DC20 check} \\ \text{(40–41 damage taken)}& \rlap{\text{Ability Modifier}}\\ \text{Check Type} & -3 & -2 & -1 & 0 & 1 & 2 & 3 & 4 & 5\\ \hline \text{disadvantaged} & 0\text{%} & 0\text{%} & 0\text{%} & 0.25\text{%} & 1\text{%} & 2\text{%} & 4\text{%} & 6\text{%} & 9\text{%} \\ \text{regular} & 0\text{%} & 0\text{%} & 0\text{%} & 5\text{%} & 10\text{%} & 15\text{%} & 20\text{%} & 25\text{%} & 30\text{%} \\ \text{advantaged} & 0\text{%} & 0\text{%} & 0\text{%} & 10\text{%} & 19\text{%} & 28\text{%} & 36\text{%} & 44\text{%} & 51\text{%} \\ \end{array}

I would also note that the Resilient feat you mentioned in your question does not give you advantage on the Saving Throw, simply proficiency in it. Proficiency varies drastically by character level, making the early level payoffs on concentration checks not as good, and the high level payoffs are of a similar order of magnitude as the advantage from War Caster, depending on your starting point.

In addition to this, if the player already has proficiency in Con STs from other sources they can still get good value out of the War Caster feat, while they won't from Resilient.

So the Resilient feat does not replicate the advantaged concentration Saving Throw feature of War Caster.

The Opportunity Attack (OA) modification enables casters to cast touch range spells as an OA, some of which can be particularly problematic for the recipient. Contagion, Bestow Curse and Inflict Wounds are good examples of this.

There are also combat situations where you may not want/be able to drop your weapon and pick it up again. For example, if you are grappled or restrained the potential for your DM to rule that picking up a weapon requires a full action is increased. In particular the illustrations in the PHB of the Grappled and Restrained conditions give the strong impression that certain free actions might be difficult when these conditions are applied, and thus require a full action. War Caster enables you to cast spells with a Somatic component in those situations without having to potentially use up a full action.

Answer 4

No

From the answer you linked:

Note that you are allowed to interact with only one object per turn for free (p. 190, Other Activities on Your Turn, PHB). This means that you can draw or sheathe a weapon for free as part of another action (such as a move or attack), but to do both in the same turn you'll need to take the Use an Object action or have the Dual Wielder Feat (p. 165, Feats, PHB).