Needing War Caster feat on a polearm user... Do I really?

[Windrammer]

It's not like a glaive falls out of your grasp the minute you take a hand off. Is it a matter of suspending disbelief for the sake of balance, or what?

If you needed both hands free I'd understand, but you don't, so what gives?

[Slipperychicken]

IIRC, you can take one hand off the the weapon just long enough to cast a spell, then go back to two-handing. Can't find the source of that right now, though.

[MukkTB]

Older editions doing this qualified as a free action. This edition, IDK.

[Shadow]

It's not like a glaive falls out of your grasp the minute you take a hand off. Is it a matter of suspending disbelief for the sake of balance, or what?

If you needed both hands free I'd understand, but you don't, so what gives?

The suspension of disbelief part for me is the idea that you can defend yourself while wielding a huge (and unwieldy) two handed weapon in only one hand.
By the book you can simply drop a hand for a moment. But every single thing about that feels wrong to me and always has. Previously you'd take an OoA for casting in melee, which made perfect sense (since you are now not defending yourself effectively). But now there is zero downside.
It's one of the few things that I don't like about 5e, and I have houseruled that wielding a two-hander in melee and casting a spell with any somatic components grants an OA unless you have the Warcaster feat. You have lowered your defenses to cast that spell. There needs to be repercussions for doing so.

[Windrammer]

The suspension of disbelief part for me is the idea that you can defend yourself while wielding a huge (and unwieldy) two handed weapon in only one hand.
By the book you can simply drop a hand for a moment. But every single thing about that feels wrong to me and always has. Previously you'd take an OoA for casting in melee, which made perfect sense (since you are now not defending yourself effectively). But now there is zero downside.
It's one of the few things that I don't like about 5e, and I have houseruled that wielding a two-hander in melee and casting a spell with any somatic components grants an OA unless you have the Warcaster feat. You have lowered your defenses to cast that spell. There needs to be repercussions for doing so.

Can you point me to where in the book it says I can take a hand off? I'll need this for the DM, thank you very much.

As for your perspective.. You don't actually defend yourself with the weapon, as it doesn't give you AC. You are at no disadvantage if you dropped the weapon at your feet by rules as written. But the AOO rule sounds reasonable.

[Shadow]

Can you point me to where in the book it says I can take a hand off? I'll need this for the DM, thank you very much.

As for your perspective.. You don't actually defend yourself with the weapon, as it doesn't give you AC. You are at no disadvantage if you dropped the weapon at your feet by rules as written. But the AOO rule sounds reasonable.

If you search/scour thesageadvice.com you'll see varying answers to this. Mearls says no casting. Crawford says it's fine. Crawford is generally accepted as the rules guy (even by Mearls).
Basically it's the DM's call, but the rules guy says it's fine.

As for the other point, we were talking about suspension of disbelief, not of rules. The rules (or lack thereof in this case) is what suspends disbelief. It doesn't matter if the rules have nothing to do with defending yourself with a weapon. Common sense says that is exactly what is happening. If you are in melee with a weapon, you are using it to defend yourself as much as to attack, if not more.

[Daishain]

Can you point me to where in the book it says I can take a hand off? I'll need this for the DM, thank you very much.

It is not in the book. One of the developers, when asked about it, effectively stated that taking a hand off a two hander to cast a spell was a free action. I forget who said it at the moment though

Edit: yeah, what Shadow said. Including the bit about weapons being used more often for defense than attack.

[silveralen]

Technically speaking, you can sheathe your weapon as your item interaction, the draw it next turn as your item interaction. The only downside to doing that would be losing an attack of opportunity. So at the very least you can fall back on that, and depending on your class you might want to check if the spell even has somatic components (paladin and ranger list tends to have fewer for example).

Of course that's by strict raw, Crawford gives the more reasonable interpretation imo.

[RedMage125]

I think imposing an AoO is a bit too harsh, especially considering that a single-classed wizard wearing NO armor and wielding NO weapon does not provoke an AoO when casting in melee. Why would this polearm-wielding caster have a worse time of it?

Casters get DISADVANTAGE when they cast spells in melee, and ONLY if it's a Ranged spell, just like a martial character firing a crossbow when he's in melee. No AoO.

AoOs in this edition seem to be exclusively for when you leave a threatened space without taking the Disengage action.

[Feldarove]

Like people are saying, you don't need to the feat to cast a spell and wield a two-handed weapon.

I think it makes perfect sense. There are plenty examples of people using a two handed weapon then putting it in one hand and doing something with the off hand.

Darth Maul using his two handed light sabre in one hand from time to time is one that comes to mind. (Not exactly the same as a glaive, but its just what popped up in my head).

My group has always played that you attack (or react) with two-handed weapons, but you can hold them in one hand while performing another action.

Even Defensively, I can see holding a weapon in one hand and still being able to hold off attacks, not enough to garner a bonus to AC, but I think all the flavor works out.

We are playing Awesome Adventurers! My 16 str dragonborn fighter is much more capable than myself with a glaive!

[odigity]

What about sword and shield? I'm playing a Fighter 1 / Wizard 2 (Abjurer) with longsword and shield right now, and just casting spells when I feel without worrying too much about hands. Is that bad? I really don't want to waste a feat just to be functional...

[Shadow]

What about sword and shield? I'm playing a Fighter 1 / Wizard 2 (Abjurer) with longsword and shield right now, and just casting spells when I feel without worrying too much about hands. Is that bad? I really don't want to waste a feat just to be functional...

That requires Warcaster or sheathing the blade/stowing the shield. No room for DM fiat unless he simply ignores the rules for you.
Sheathe for free > cast. Next round draw for free if you want to attack. No OAs after casting until your next turn (if you draw it again next turn).

[RedMage125]

No OAs from casting a spell anyway.

If you're going to talk about what a strict reading of the rules say, Shadow (such as needing a free hand to cast a spell), you should also not propose things that are NOT in the rules. According to page 195 of the PHB, only moving out of an enemy's reach without disengaging provokes an AoO. Casting a spell in melee causes disadvantage on the attack roll ONLY if the spell is a ranged spell. Melee spells such as shocking grasp have no penalty.

[odigity]

No OAs from casting a spell anyway.

If you're going to talk about what a strict reading of the rules say, Shadow (such as needing a free hand to cast a spell), you should also not propose things that are NOT in the rules. According to page 195 of the PHB, only moving out of an enemy's reach without disengaging provokes an AoO. Casting a spell in melee causes disadvantage on the attack roll ONLY if the spell is a ranged spell. Melee spells such as shocking grasp have no penalty.

This is why it's important to quote the thing you're responding to. I assume you were responding to the post immediately before yours, by Shadow, which was a response to me. If so, you misunderstood him. He was just pointing out that by sheathing your sword until the following turn, you miss out on an opportunity attack if any foes decide to leave your reach during that time. He was NOT proposing that simply casting a spell triggers an AoO.

[Windrammer]

If you search/scour thesageadvice.com you'll see varying answers to this. Mearls says no casting. Crawford says it's fine. Crawford is generally accepted as the rules guy (even by Mearls).
Basically it's the DM's call, but the rules guy says it's fine.

As for the other point, we were talking about suspension of disbelief, not of rules. The rules (or lack thereof in this case) is what suspends disbelief. It doesn't matter if the rules have nothing to do with defending yourself with a weapon. Common sense says that is exactly what is happening. If you are in melee with a weapon, you are using it to defend yourself as much as to attack, if not more.

The case you're making may as well be that weapons should give you AC. If you have no weapon in your hands, there is no change in your ability to defend yourself, by the rules. If taking a hand off to cast a spell hinders your defenses then you should be getting some sort of defensive benefit to keeping a weapon in hand.

[mr_odd]

So, after rereading some sections in the PHB, the conclusion that I have come to is this: when casting a spell while holding weapons, you are unable to react to an attack of opportunity, unless you have the War Caster feat.

Dropping a hand on a two handed weapon, and sheathing a sword while you have a shield should result in the same thing. They are both doable without War Caster, but again, they do not get attacks of opportunity. Also to note, a character with a one handed weapon and no shield can cast just fine.

And in reality, this ruling does not water down War Caster, its other benefits are still pretty good.

[RedMage125]

So, after rereading some sections in the PHB, the conclusion that I have come to is this: when casting a spell while holding weapons, you are unable to react to an attack of opportunity, unless you have the War Caster feat.

Dropping a hand on a two handed weapon, and sheathing a sword while you have a shield should result in the same thing. They are both doable without War Caster, but again, they do not get attacks of opportunity. Also to note, a character with a one handed weapon and no shield can cast just fine.

And in reality, this ruling does not water down War Caster, its other benefits are still pretty good.
I'm a little unclear on whether you have it down or not, because of the way you worded that. I'll break it down, and if you already had it, I apologize.

If a spell has somatic components, you cannot cast it unless you have a hand free. With a weapon or shield in both hands, you cant make the gestures necessary to cast the spell. If you have War Caster, you can. Someone with a two-handed weapon may, on their turn, hold the weapon in only one hand in order to cast a spell.

Even if you have a hand free, you cannot use a spell or cantrip to make an AoO when an enemy provokes one from you unless you have War Caster. Even a melee spell with a casting of one action, like Shocking Grasp requires War Caster to be used as an attack for an AoO.

So the sorcerer without this feat who's holding nothing in his hands and has spent the last 2 rounds casting shocking grasp on a hobgoblin cannot use shocking grasp when the hobgoblin moves out of his threatened area. But the cleric with this feat who's been swinging in melee for the last 2 rouds can, with shield in one hand, warhammer in the other, could cast hold person on that same hobgoblin as an attack of opportunity.

The spell that someone with War Caster can cast as an AoO need not even be an attack spell. Any single-target spell with a 1 Action casting time will do.

[odigity]

Even if you have a hand free, you cannot use a spell or cantrip to make an AoO when an enemy provokes one from you unless you have War Caster. Even a melee spell with a casting of one action, like Shocking Grasp requires War Caster to be used as an attack for an AoO.

I was about to post a correction saying that AoO is limited to melee weapon attack, which is why you need War Caster, but when I went to check, I discovered it only specifies "melee attack" nor "melee weapon attack", so you actually can cast Shocking Grasp in response to an AoO trigger *without* War Caster! Nice.

Obviously you'd still want War Caster if you prefer to use ranged or save-based attacks, like Eldritch Blast or Sacred Flame, or even Hold Person (single-target version).

[bloodshed343]

If you search/scour thesageadvice.com you'll see varying answers to this. Mearls says no casting. Crawford says it's fine. Crawford is generally accepted as the rules guy (even by Mearls).
Basically it's the DM's call, but the rules guy says it's fine.

As for the other point, we were talking about suspension of disbelief, not of rules. The rules (or lack thereof in this case) is what suspends disbelief. It doesn't matter if the rules have nothing to do with defending yourself with a weapon. Common sense says that is exactly what is happening. If you are in melee with a weapon, you are using it to defend yourself as much as to attack, if not more.

By your distorted logic, Wizards without weapons should provoke attacks of opportunity when they enter melee, since they have no way to defend themselves without wielding a weapon.

Unarmed four elements monks should provoke attacks of opportunity for casting a spell with ki points, since they don't have a weapon to defend themselves.

If an enemy disarms you, you should provoke attacks of opportunity because you don't have a weapon to defend yourself.

If you attempt a grapple with a two handed improvised weapon using the tavern brawler feat, you should provoke attacks of opportunity because you have to take your hand off the weapon.

Not only are these things inconsistent with the rules, some of them are inconsistent with reality. Does a knight who drops his sword suddenly lose his armor and shield as well? Does a swashbuckling forget his footwork if he drops his cutlass?

You seem to be arbitrarily punishing certain players for no other reason than because you can.

[Shadow]

By your distorted logic,

First of all, take it easy there, chief.

Secondly, none of what you just said was true (except the tavern brawler thing.... almost.... because I'd give disadvantage on the grapple attempt and an OA provocation every round you tried to hold both the enemy and the two-hander).
Go get a 5 pound sledge hammer and attach it to an extra long broomstick. Hold it in one hand and see if you can swing it effectively. See if you can even move quickly/precisely/effortlessly.
You can't. You can't defend yourself at all because not only can you not use the weapon, you also can't dodge effectively anymore.
A monk/wizard/disarmed character/whatever can still dodge, dip, dive, duck and dodge.
A person holding a 5 lb sledge on a long broomstick in a single hand cannot.

It's also a bit of a balancing factor for melee vs caster. If you want to use a two-handed weapon as a caster, you need to spend a feat to be able to do both effectively.

But like I said from the get go, it's a houserule. I never said that anyone else should use it, I said that I use it.

[RedMage125]

It's also a bit of a balancing factor for melee vs caster. If you want to use a two-handed weapon as a caster, you need to spend a feat to be able to do both effectively.

But like I said from the get go, it's a houserule. I never said that anyone else should use it, I said that I use it.

See, now I missed that, too. I genuinely thought you were trying to advocate that the RAW said this. Sorry.

[silveralen]

First of all, take it easy there, chief.

Secondly, none of what you just said was true (except the tavern brawler thing.... almost.... because I'd give disadvantage on the grapple attempt and an OA provocation every round you tried to hold both the enemy and the two-hander).
Go get a 5 pound sledge hammer and attach it to an extra long broomstick. Hold it in one hand and see if you can swing it effectively. See if you can even move quickly/precisely/effortlessly.
You can't. You can't defend yourself at all because not only can you not use the weapon, you also can't dodge effectively anymore.
A monk/wizard/disarmed character/whatever can still dodge, dip, dive, duck and dodge.
A person holding a 5 lb sledge on a long broomstick in a single hand cannot.

It's also a bit of a balancing factor for melee vs caster. If you want to use a two-handed weapon as a caster, you need to spend a feat to be able to do both effectively.

But like I said from the get go, it's a houserule. I never said that anyone else should use it, I said that I use it.

The feat still isn't worth it unless you already have con prof, as using a longsword or battle axe and changing your grip is easy and obviously works 100%. War caster is the sort of feat tax they did a great job removing elsewhere, the only other big "must take this feat for your character concept to work at all" being the duel wielder feat potentially.

It's forcing characters to pay a tax to realize a concept, rather than taking the feat to boost their effectiveness. That's not my idea of a good feat.

[mr_odd]

I'm a little unclear on whether you have it down or not, because of the way you worded that. I'll break it down, and if you already had it, I apologize.

If a spell has somatic components, you cannot cast it unless you have a hand free. With a weapon or shield in both hands, you cant make the gestures necessary to cast the spell. If you have War Caster, you can. Someone with a two-handed weapon may, on their turn, hold the weapon in only one hand in order to cast a spell.

Even if you have a hand free, you cannot use a spell or cantrip to make an AoO when an enemy provokes one from you unless you have War Caster. Even a melee spell with a casting of one action, like Shocking Grasp requires War Caster to be used as an attack for an AoO.

So the sorcerer without this feat who's holding nothing in his hands and has spent the last 2 rounds casting shocking grasp on a hobgoblin cannot use shocking grasp when the hobgoblin moves out of his threatened area. But the cleric with this feat who's been swinging in melee for the last 2 rouds can, with shield in one hand, warhammer in the other, could cast hold person on that same hobgoblin as an attack of opportunity.

The spell that someone with War Caster can cast as an AoO need not even be an attack spell. Any single-target spell with a 1 Action casting time will do.

Yes, that is exactly what my thoughts were. I realize my wording could have been more specific, but nevertheless thank you for the break down.

[bloodshed343]

First of all, take it easy there, chief.

Secondly, none of what you just said was true (except the tavern brawler thing.... almost.... because I'd give disadvantage on the grapple attempt and an OA provocation every round you tried to hold both the enemy and the two-hander).
Go get a 5 pound sledge hammer and attach it to an extra long broomstick. Hold it in one hand and see if you can swing it effectively. See if you can even move quickly/precisely/effortlessly.
You can't. You can't defend yourself at all because not only can you not use the weapon, you also can't dodge effectively anymore.
A monk/wizard/disarmed character/whatever can still dodge, dip, dive, duck and dodge.
A person holding a 5 lb sledge on a long broomstick in a single hand cannot.

It's also a bit of a balancing factor for melee vs caster. If you want to use a two-handed weapon as a caster, you need to spend a feat to be able to do both effectively.

But like I said from the get go, it's a houserule. I never said that anyone else should use it, I said that I use it.

Your original reason was that weapons are used defensively, and that therefore losing your ability to use a weapon effectively means that you drop your defences.

A greatsword is only 2 pounds heavier than a battle axe, which is a one handed weapon. It actually weighs the same as a shield. If you grant AoOs for holding a 6 pound weapon in one hand, then shields should give you a penalty to ac instead of a bonus, because they weigh the same. Even if you can't swing it effectively with one hand, you can still hold it and parry. If you can't dodge effectively wielding a greatsword in one hand, then you can't dodge with a battle axe and shield either.

The heaviest weapon is the pike (18 lbs, isn't a heavy weapon), however, you can shift your grip up the haft to balance it out and parry with the haft. You could also plant the haft on the ground and Parry across your body.

With a two-handed improvised weapon, unless it weighed more than 20 pounds, it should be easy to hold in one hand. The average person can easily manipulate a 6 pound object with one hand, so a super humanly strong, well trained fighter should have no problem dodging/parrying while holding a two handed weapon with one hand.

Another problem is that you only take your hand off for a single action, then put your hand back on. By your reasoning, not having a second hand on a greatsword is exactly as dangerous as turning your back to the enemy mid-fight, even if you only take your hand off for a second. What happens if you take your hand off to point something out to an ally? What if you drink a potion? What if you need to wipe the sweat out of your eyes?

Not only that, but casting a spell is an offensive action, like an attack, that the enemy has to respond to. If you cast Burning Hands, any enemy that made an attack of opportunity should fail the save automatically because they attacked instead of dodging.

Also, if you're attacking with a weapon, you aren't using it for defense or protecting yourself for the duration of that action. If taking your hand off a weapon for one action to cast a spell grants an attack of opportunity, then attacking with a two-handed weapon should provoke as well, since in neither case are you actively defending yourself.

Of course, you're free to run your game however you want. I don't mean anything against you personally, just that the justification for this rule isn't consistent with other game elements.

Edit: I also didn't catch that this was your house rule at first. I thought you were arguing RaI.

[metaridley18]

On a related note: Wizards, Sorcerers and Warlocks can use a staff as an arcane focus. Most magical staves say they can be used as a quarterstaff, so depending on GM it is likely a reasonable interpretation that the arcane focus staff can be used as a quarterstaff as well. The improvised weapon rules follow this logic as well, saying that an improvised weapon can be treated as any weapon it similarly shaped to.

When using a focus (or a component pouch for that matter), you can make the somatic component with the same hand that wields the focus.

Putting it all together, can you have a staff wielding caster who casts spells with his weapon and basically gains that portion of the Warcaster feat for free? Combine with Polearm Master for maximum cheese effectiveness.

[Knaight]

Go get a 5 pound sledge hammer and attach it to an extra long broomstick. Hold it in one hand and see if you can swing it effectively. See if you can even move quickly/precisely/effortlessly.
You can't. You can't defend yourself at all because not only can you not use the weapon, you also can't dodge effectively anymore.
What you've described is a clumsy piece of junk, poorly weighted and significantly harder to handle than just about any real pole arm. Using a polearm in one hand is way less effective than using it in two, but you can still move.


Your original reason was that weapons are used defensively, and that therefore losing your ability to use a weapon effectively means that you drop your defences.

A greatsword is only 2 pounds heavier than a battle axe, which is a one handed weapon. It actually weighs the same as a shield. If you grant AoOs for holding a 6 pound weapon in one hand, then shields should give you a penalty to ac instead of a bonus, because they weigh the same. Even if you can't swing it effectively with one hand, you can still hold it and parry. If you can't dodge effectively wielding a greatsword in one hand, then you can't dodge with a battle axe and shield either.

Weight isn't a very good sole metric. For instance, there have been 20 pound shields in use, and they're usable in one hand. A 20 pound sword is just about completely useless. The difference is in torque more than weight, where the torque of the shield upon your hand is relatively minimal as the mass generally doesn't protrude too far out (though it is worth noting that there are a number of techniques with lighter shields that do involve aggressively using the edge, that are going to make one of the really heavy specimens near uncontrollable).

I personally wouldn't implement the AoO, mostly because the clear trend in D&D is to not have it be all that dangerous to be in melee without a proper weapon. There are no free attacks against people with just a bow, being unarmed doesn't negatively impact AC, so on and so forth. I'd have loved to see AC broken into ranged and melee with melee weapons providing a bonus to melee AC, but as that didn't happen there isn't a very good way to model the clumsiness of using a two handed weapon in one hand with the system.

[RedMage125]

I was about to post a correction saying that AoO is limited to melee weapon attack, which is why you need War Caster, but when I went to check, I discovered it only specifies "melee attack" nor "melee weapon attack", so you actually can cast Shocking Grasp in response to an AoO trigger *without* War Caster! Nice.

Obviously you'd still want War Caster if you prefer to use ranged or save-based attacks, like Eldritch Blast or Sacred Flame, or even Hold Person (single-target version).

I'm going to have to disagree, since Shocking Grasp has a casting time of one ACTION, and not one REACTION (and since spells like Feather Fall and Hellish Rebuke do have casting times of one reaction, I don't think this was an oversight).

Making a weapon attack normally requires an Action, but the rules regarding Attacks of Opportunity are a Specific Exception, allowing a character to make an attack as a Reaction when provoked.

Given that War Caster explicitly, as a benefit of the feat, allows for a spell with a normal casting of an Action to be cast as an AoO (and thus a reaction), I think it's clear that it is not permissible without the feat.

Now, if your DM allows you to "hold a charge" with a touch-range spell (let's say you used your last action to cast Shocking Grasp, but did not attempt to hit with it, so you are "holding" the spell), I'd say you could use it as an AoO, even without the feat. But otherwise, you'd need to use a Readied Action (which also allows you to perform an activity with a normal Action cost as a Reaction). But that's dependent on DM fiat, since there are no clear rules regarding "holding a charge"

[Draken]

What class are you playing, precisely?

Depending on answer, you could probably ask your DM about making the glaive into an implement (Staff or Holy Symbol).

Shouldn't be too complicated either way.

[MaxWilson]

If you search/scour thesageadvice.com you'll see varying answers to this. Mearls says no casting. Crawford says it's fine. Crawford is generally accepted as the rules guy (even by Mearls).
Basically it's the DM's call, but the rules guy says it's fine.

Even Mearl sometimes says it's fine, e.g. in this tweet: https://twitter.com/mikemearls/status/504001681689169920

So apparently he goes back and forth.

[Shadow]

So apparently he goes back and forth.

Yeah, apparently he does, because I was referring to this one. (https://thesageadvice.wordpress.com/2014/09/01/casting-with-a-2h-weapon/)

[Maxilian]

First of all, take it easy there, chief.

Secondly, none of what you just said was true (except the tavern brawler thing.... almost.... because I'd give disadvantage on the grapple attempt and an OA provocation every round you tried to hold both the enemy and the two-hander).
Go get a 5 pound sledge hammer and attach it to an extra long broomstick. Hold it in one hand and see if you can swing it effectively. See if you can even move quickly/precisely/effortlessly.
You can't. You can't defend yourself at all because not only can you not use the weapon, you also can't dodge effectively anymore.
A monk/wizard/disarmed character/whatever can still dodge, dip, dive, duck and dodge.
A person holding a 5 lb sledge on a long broomstick in a single hand cannot.

It's also a bit of a balancing factor for melee vs caster. If you want to use a two-handed weapon as a caster, you need to spend a feat to be able to do both effectively.

But like I said from the get go, it's a houserule. I never said that anyone else should use it, I said that I use it.

I understand, but what about versatile weapons (like Quaterstaffs)? wouldn't it work perfectly with versatile weapons (as long as you're using it as a 2-handed weapon and when you're going to cast a spell, as a 1 handed weapon)

[Dalebert]

I don't get the impression that somatic components of spells are typically very elaborate. You say a few words and you point at a target to direct the spell. So you let go of your polearm for a moment. Maybe the tip even hits the ground for a moment. Maybe it's standing at your side like a staff and it starts to lean over for a moment. Then you grab it with both hands and are back in action. Now, you're not grabbing it fast enough to get an AoO with it that same round but you're ready for your action in your next round.

You can certainly choose to make it more complicated than that but making things more complicated seems out of flavor (in general) for this edition. If you're using a lot of optional combat rules to make combat more interesting and want to further make martial characters more interesting vs. casters, it fits more with that flavor to make casting more complicated.

You can draw or sheath a weapon as part of an action to attack and letting go of a weapon and putting a hand back on it have to be at least as trivial. I'd say if you house rule this to be more complicated, you should also house rule away the sheathing and drawing of a weapon as part of your attack action.

[Knaight]

I don't get the impression that somatic components of spells are typically very elaborate. You say a few words and you point at a target to direct the spell. So you let go of your polearm for a moment. Maybe the tip even hits the ground for a moment. Maybe it's standing at your side like a staff and it starts to lean over for a moment. Then you grab it with both hands and are back in action. Now, you're not grabbing it fast enough to get an AoO with it that same round but you're ready for your action in your next round.

Plus, if they are elaborate then you should still be vulnerable even with a one handed weapon. If you're in a sword fight and need to stay in a position for elaborate arm and hand movements rather than being able to freely move the arm, you're going to have trouble.