Many of the spells that an Eldritch Knight can cast have a somatic component. If I am playing as an Eldritch Knight with a two-handed sword or weapon/shield combo, would I require the Warcaster feat?
The way I see it is that the Warcaster feat's intention was to allow those with two-handed weapons, dual wielding or sword/shield setup to cast spells, meaning that by default, Eldritch Knights shouldn't be able to cast spells with somatic components without the feat.
You can't cast spells while holding your two-handed sword or your sword and shield without the War Caster feat. This is spelled out on page 203 of the PHB:
If a spell requires a somatic component, the caster must have free use of at least one hand to perform these gestures.
However, you don't necessarily need to take the feat in order to use a two-handed sword or a sword and shield and cast spells. (I realise the previous sentence seems to contradict the first one, but I'm getting there.)
Each turn, you can interact with one object without using an action. (See page 190 of the PHB for details.) If you are using a sword and shield, this means you can, for example, sheathe your sword without using an action, then cast a spell on the same turn. Then next turn, when you want to attack with your sword, you can draw it without using an action, then attack on the same turn. Note that this leaves you unable to take opportunity attacks between these 2 turns.
You can find more information about wielding weapons and casting spells without War Caster here, here, and here.
As the other answers said, you don't get to cast spells with a somatic component if you're wielding a sword and shield without the War Caster feat. However, the eldritch knight does get the Weapon Bond feature, which allows him to summon his weapon to his hand, as long as it's on the same plane of existence, as a bonus action. So a workaround to this would be to drop your sword as a free action, cast your spell as your action, and summon the sword as your bonus action. This is available as soon as you get the eldritch knight archetype, and it only takes 1 hour to complete the ritual to create a bond with a weapon. This is also useful for quickly switching between two weapons, as you can bond with up to two weapons at a time.
I looked around a bit at rules clarifications by the devs, and found this tidbit:
Any advice on handling Clerics/druids with shields and spell casting? They seem disadvantaged without a hand free for S/M comps.
just stow that weapon in the shield hand for a moment and you're good - the rule isn't there to restrict, but to clarify. -Mcan you cast a spell that uses somatic components if you wield a 2-handed weapon or a versatile weapon in 2 hands?
nope. -M
What this basically means is that, as long as you're not dual wielding weapons or using two-handed weapons, the somatic component of spells don't actually matter much in combat. This does make that part of the warcaster feat a little irrelevant, and it is up to your DM whether or not he would allow it.
While actually wielding a two-handed weapon, or a weapon and a shield, you normally won't be able to cast spells with somatic components.
However, in the two-handed case, you can release the grip on the weapon with one hand in order to cast. After all, unless you're super-weak, you'll be able to hold the thing with one hand - just not attack with it like that. I'm not sure this has any actual rule support, but it seems reasonable to allow on grounds that dropping an item is a free action.
And in the sword-and-board case, have you considered a buckler? They leave a hand free.
I'd say it works in these three ways
Sword and shield. Drops weapon/stabs into ground (1 free action) then casts spell (1 action). Using magic bond, picks up weapon (1 bonus action). This example prevents players shield bashing for free or having a high AC with no set back to versatility between weapons and magic.
Two handed weapon. Same as first. I would say I drop the weapon against the ground but wield it with one hand (1 free action), cast spell (1 action), magic bond weapon back to hand (bonus action). This example doesn't allow players to use bonus actions.
Versatile weapon. Holding sword in two hands, removes one hand to casts spell. Places hand back. Still has a bonus action and free interaction with doors and other stuff.
Let's be honest, if you need a spare hand to cast a spell, then you're going to have to go with versatile weapons.
If you want your character to be the master of casting with weapons, War Caster it is.
You can cast spells even without the feat by doing the following:
Just make sure you don't move after dropping your weapon and before picking it up. That bullet point of War Caster is really only good for letting you move, it seems. And it removes the need to drop your weapon like maybe if you're doing water/aerial/mounted combat.
jon and bob's answer has the right idea. I have DM'd D&D games for over ten years and I can see the devs slowly working towards resolving some of the glaring issues that are present in the game mechanics. That said, they cannot account for everything. That is why, in every single chapter of the Player's Handbook, you are explicitly told that the RAW are intended to guide character creation and gameplay, not constrain it.
If you're wielding a two-handed weapon and you have the War Caster feat, the rules say that you can still cast the spell (I imagine, in the example case of the burning hands spell, it would involve pouring magic into your sword, limning it with flames, and then swinging the sword in a large arc that sends the flames out in a cone). Without the War Caster feat, I wouldn't say that you would have to drop the two-handed sword, only that you would have to balance it in such a way (say, against your shoulder) that you can get a free hand to cast the spell. I would then say that you make opportunity attacks with disadvantage until the start of your next turn because you had to sacrifice proper sword-fighting form in order to cast the spell. Of course, if it's a more complex spell such as a ritual in which you need to do tasks that would reasonably require two hands, then you should be putting away your sword.
Again, this isn't necessarily RAW, but you are told dozens of times throughout the PHB that the RAW are not always comprehensive enough to account for the variety of circumstances that occur in a game. Discuss it with your DM to make sure you are both on the same page. He or she may decide that you can't take any opportunity attacks with a two-handed weapon if you have cast a spell in the previous turn without the War Caster feat. Don't be afraid to come up with an independent solution (sometimes pejoratively called a "house rule") for situations like this. There's nothing wrong with making up an answer in order to clarify gameplay, especially if perusing the books and querying on the internet would hold up the game. And don't be afraid to make rulings that favour a player's convenience. Remember that the characters are the highest calibre of heroes (or anti-heroes) who are capable of exploiting every advantage they can find in order to increase their odds of survival and success.
Happy gaming!
Drop your weapon bonded weapon, cast your spell, while retaining your shield, or drop the two-handed weapon, although why you would not be able to hold a two-handed weapon in one hand while you casting I am not certain? If nothing else, you could hold a two-handed weapon like a rifle leaning against your shoulder, or carry it in weapon carrying position or rest position in case of a halberd or spear, etc.
But lets just go with you drop your two-handed weapon...or your one-handed weapon...
Using Weapon Bond you can summon your weapon back into your hand as your bonus action. Your shield was never dropped, so you have your shield AC and your weapon is in hand...
Weapon Bond. Over the course of 1 hour short rest, you can bond a weapon to you. Once bonded, you cannot be disarmed unless you are incapacitated and if the weapon is on the same plane of existence, you can summon it to your hand as a bonus action. You can bond up to two weapons at once.
