I've got a level 5 pure Hexblade (Pact of the Blade) Warlock that I am running right now and while I love him, I am having a really hard time adjusting to the whole 2 spell slots/uses thing. We just got done going thru a dungeon that had a good number of battles in it and after every battle I was like "Can we take a short rest? I don't have any spells" It got a little annoying for me, and the DM and group as whole I would guess. Especially since I'm kinda the main magic user in our group. There were more than a few times that we didn't take a short rest and we went into another battle and people at my table were like "hey, isn't there some magic stuff you could do to help us out?" And I had to tell them "sorry, no spells left".

So my question is how do you run a Warlock optimally and efficiently with just the 2 spell slots (till what, level 10 ?) I just feel that I am not very useful because I am always out of spells and basically just Eldritch Blast or hit things with my sword and it makes combat a little boring and repetitive. So any suggestions on how I can play better / more efficiently would be greatly appreciated.

Warlocks are Cantrip casters with a couple of spell slots and Eldritch Invocations.  They're not full casters and they weren't meant to be.  In combat they're not that different from PC's who specialize in bows, only Eldritch Blast never runs out of arrows.  The Hexblade let's Warlocks fight in melee the way Paladins do because both can use spell slots to Smite, but that doesn't change the fundamental nature of Warlocks.

I'd talk with your DM about switching a one of your Cantrips around for one that can be more flexible in addition to keeping Eldritch Blast.  

• Create Bonfire is great under an opponent who is in melee with a couple of members of your party.  The opponent has to either stay there and take damage from the spell, use their action to Disengage, or retreat and suffer Attacks of Opportunity.
• Lightning Lure can pull that annoying spell caster into melee with you and the rest of your friends who like beating on things with sharp, pointy sticks. Especially if you're able to follow it up with Booming Blade the next round.
• Minor Illusion is only limited by your imagination.  Prepare a bunch of illusions ahead of time and have fun with them.  
• You can also be creative with Mage Hand and Prestidigitation in combat.  Just because they can't cause damage that doesn't mean you can't use Mage Hand to spread Ball Bearings or Caltrops behind an opponent who looks like he's getting ready to flee for example.

To me Warlocks are the most fun in campaigns that are heavy on role playing the same way Bards are.  Both can be fun in campaigns that are heavy on roll playing, but they're more fun where there's a lot of role playing.  The Hexblade sacrifices a lot of the role playing opportunities because you're almost forced to use most of your Eldritch Invocations to enhance your weapon combat enough to hold your own side by side with a Paladin, but the flip side of that is you can stand toe to toe with a Paladin as a Hexblade while other Warlocks need to keep their distance from melee.

Start thinking about your Warlock as a Fighter/Paladin/Barbarian/Ranger in combat with a couple of spells instead of thinking of him as a spell caster and have fun with him the way he is instead of trying to make him into something that he isn't.  I hope this helps.

Thanks Tim! This was a very helpful and thought out response. I appreciate it.

The role play aspect is why I leaned towards building a Warlock originally. I've got a pretty good backstory written for him, and the DM is helping me slowly roll it out. But the DM is also giving me an out to change to a new character because he see's that I'm not having that much fun in combat playing with him. Also our table group consists of a Barbarian, a Rogue, a Bard, and an on again off again Fighter. So we really don't need another front line fighter type. So I got decisions to make I guess...

One more question I guess ? I originally was going to make a Pact of the Tome / Fiend Patron Warlock but came across the Hexblade and figured it would be more versatile so that's why I went that direction. So my question... Wouldn't these Warlocks not being able to to be a front line fighter be even more pigeon-holed into hanging back and casting Eldritch blast most of the time because they are "basically" full fledged spell caster with very minimal spell slots ? Or is there a whole bunch of stuff I'm missing ? There probably is...... ugh.

In combat, warlocks mostly either spam Eldritch Blast or take the Hexblade patron and fight using weapons.  That's not necessarily bad unless you want the versatility of playing a wizard.  The way I play my warlock in combat is I save his spell slots for when they'll be the most effective and depend on his cantrips most of the time.  Out of combat I use his spell slots regularly and about half of his spells are non-combat spells.  Comprehend Languages is a non-combat spell and Hex is just as great out of combat as it is in combat when you use it to "kneecap" someone's ability checks.

I'd switch away from being a Hexblade to being a Fiend warlock since you like the flavor of the fiend.  Your party doesn't need another weapon oriented character.  Then pick 2 Eldritch Invocations that aren't related to Eldritch Blast that will give you fun and creative things to do with him.  And use your 2 spell slots carefully when they'll have the most impact when you're likely to have a few encounters in a row without short rests between them.  On the other hand when you're likely to have a long rest between encounters, use those spell slots up quickly to get the encounters over with!

Here's my warlock who I'm playing right now.  Dunkan The only reason why he learned Fire Bolt is to target objects because it's one of the few spells that catches objects on fire when it targets an object instead of a creature.

For my Hexblade, I try to follow these rules for using a spell slot:

1. Save your spells for when they're really matter.  
   1. For example, the most difficult encounter comes at the end of a dungeon.  Try to save one for there.  
2. Use spells that have long durations so they're likely to be useful in multiple (or all) encounters. 
   1. Hex at level 5 is lasting for 8 hours.  That means you can use your bonus action to move it around even in different encounters.  If 8 hours have passed, you've probably had time for a short rest.
   2. Elemental Weapon is great as it lasts an hour.  It's quite possible that it will have room for a rest before the duration runs out.  This is a better option than hex because it doesn't require the bonus action to move around and provides +1 to hit at level 5.  But it does require it to be cast prior to the encounter.  If you find yourself starting a fight without this up, Hex is the better option so you don't waste a round.
   3. Suggestion has a very long duration as well and has both combat and noncombat uses.

   4. Tongues is a potentially useful noncombat spell that lasts a while.  It could possibly be used to prevent an encounter too.

3. Use spells that can be upcast.  All of the warlock spell slots are max level so using spells that have an added benefit to being cast at a higher level is very useful.
• Armor of Agathys grants you 15 temporary hit points when upcasting to a level 3 spell.  That might be increasing your hit points by a third!  Also, whenever you have at least one of those hit points and someone hits you with an attack, they take 15 damage.  It also lasts an hour.  So if you still have your temporary hit points after an encounter, they'll probably carry over to the next encounter or there will have been time for a short rest.
• Arms of Hadar can be upcast and be can be useful at area damage. 
4. Cast spells when they can be the most impactful
   1. Hunger of Hadar will likely last a whole encounter.  Using repelling blast invocation on eldritch blast is good at keeping an enemy in the dark goo.
   2. Hypnotic Pattern can change a whole encounter if cast on a large group of enemies.
   3. If you're looking at a party whipe, a hail mary like Summon Lesser Demons can change the tide.  The demons can't harm you if you stay within the summoning circle.  If you're the last person standing on your team, throwing this out there might save the day.  The demons will attack everyone and disappear after an hour, or just run away because you're blasting them with eldritch blast from inside the protected zone.

Eldritch Blast or regular weapon attacks are incredibly useful to the Hexblade.  If things are going ok, you can just stick to doing those.  Maybe find a weapon that allows you to use a bonus action to attack.  The way hexblades work, a lot of damage is added onto the weapon dice.  For example, an attack while hexblade curse and [spell]hex[/hex] is active on a target adds 1d6+3 damage in addition to your 4 charisma modifier.  If you're using a double bladed scimitar, your main attack and extra attack is 2d4+1d6+3+4.  The bonus attack is 1d4+1d6+3+4.  That bonus attack is hitting for only 1d4 less than the regular attack.  At level 12, the bonus attack is also benefitting from the Lifedrinker invocation.  The bonus attack is adding a lot of damage.  Same with polearm if you're using polearm master feat.

Yeah you're correct about the Tome/Fiend Warlock.  Eldritch Blast is going to be what you do 90% of the time.  With Agonizing blast invocation, it does good damage. There are a lot of other invocations that allow you to do other things with the Eldritch Blast like repelling blast or lance of lethargy.

There are also other invocations that grant spell casts.  Some are once per long rest, others are at will.  There are a bunch of them.  Misty Visions lets you cast Silent Image at will.  Illusion spells are limited only by your imagination.  Maybe create an image of a beholder or some other crazy thing to scare away enemies.  At level 15, Shroud of Shadow let's you cast Invisibility at will.  That's pretty crazy.  There are a lot of options there.  

Maddening Hex is fairly useful too.  A bonus action that deals 5 damage to a target and every adjacent target of your choice.  Pretty good. 

The thing to realize with warlocks is that invocations play a much larger role than spells in the average round of combat.

Wow! Great Stuff Tim and Kendis! Thanks for the very in depth replies, I truly appreciate it. You've given me A LOT to think about. Here is my current Warlock Kylothos Drakaar. I just leveled him to 5. I really enjoy him. I just kinda feel like I would be a bigger help to my party if I was a full blown Wizard maybe? Such a dilemma. A real life crisis over here! LoL

Wizards can do pretty much anything by changing their prepared spells around.  Warlocks on the other hand only do a few things but they do them very well.  Both are an absolute blast to play depending on what you prefer doing.

Quote from Tim >>

Wizards can do pretty much anything by changing their prepared spells around.  Warlocks on the other hand only do a few things but they do them very well.  Both are an absolute blast to play depending on what you prefer doing.

 I think Kylothos looks great!  Long sword and shield is a good way to go for a more defensive minded Hexblade.

My only real critique is that Vampiric Touch is not a very good spell in my opinion.  3d6 damage (average 10.5) and a heal for half (average 5.25).  That instead of doing 21 average damage per round just swinging that long sword (assuming you have Elemental weapon and Hexblade curse is active on the target).  If neither of those are up, you're doing closer 13 damage per round on average.  I also think the spell slot would almost always be better to just cast Armor of Agathys.  It does the same thing only better, although possibly for a shorter amount of time.  It only requires one action and does more damage on average while providing the hit points of 3 rounds of Vampiric Touching, on average.  It's cool flavor and situationally could be useful I suppose. 

I also think you should use Hellish Rebuke vary sparingly.  It is a cool spell in that it uses your reaction to deal damage, but I honestly don't think it's the slot for a warlock most of the time.  On average, it deals 22 damage which is a lot at level 5.  That being said, Hex does that much average damage in 3 rounds if you are hitting every time.  2 if you get to use your bonus action to attack. And hex lasts 8 hours instead of a one and done spell.  In the long run, your slot would have been much better used on Hex.  It's possible this damage would kill the target and that could definitely be useful.  That being said, your next turn will be before theirs and you'd likely kill them on your turn.  But it does free up your action to do something else.  It is very good situationally but you really have to weigh how long the encounter and adventure will be until your next short rest before using this spell.  If you find that you are often out of spells as you say, avoid this one.

I also find that spells that go against a targets spell DC to be very risky for the Warlock.  You cast one of two spells you get just to have your hold person fail would be pretty awful.  That's why I typically stick to spells that don't require a spell save.  Your Spell DC is 16 and that isn't awful though.

Personally I find Hexblades pretty engaging and don't find them boring or repetitive at all.  You just need to be careful about when and how you use your spells.

Also, take a peak at the Warcaster feat.  I think it's pretty useful in keeping up concentration on spells.  It's also required if you have a weapon and shield equipped if you want to cast spells.  Without it you would have to technically stow either your Shield or sword in order to cast a spell with somatic components.  

My solution, when possible, is to find magic items which increase your spell slots. My Warlock is at level 9 now, and I've got a Rod of the Pact Keeper which allows recovery of one spell slot per day at the cost of action. Totally worth it, even during combat, if things aren't going well.

I also have a Ring of Spell Storing, which I can use to store five extra spell levels. This one is a problem for Warlocks because all their spells are cast at max level. So a 5th level Warlock's spells are all cast at 3rd level, and you won't be able to put two spells in the ring. (That would be six spell levels.) I'd recommend storing Hex in the ring; you know you'll use it every day and it lasts 8 hours as a 3rd level spell.

A Pearl of Power can also recover a spell slot of up to 3rd level once per day, which would be useful some Warlock spells.

Quote from Kendis >>

Also, take a peak at the Warcaster feat.  I think it's pretty useful in keeping up concentration on spells.  It's also required if you have a weapon and shield equipped if you want to cast spells.  Without it you would have to technically stow either your Shield or sword in order to cast a spell with somatic components.  

  I totally want to get the Warcaster feat! Probably what I will do at level 8. However I have a question now about the the other part you said because maybe I have been misinterpreting the rules. So I got....

Actually you might be right.  I thought the same thing once upon a time but then for some reason thought u was wrong.  I'm not sure what the answer is.

I mean unless the rule means or is trying to say that " A spellcaster must have a hand free..." so have a free hand to do the Somatic Components, and then take that same free hand after doing the somatic part and grab you spellcasting focus or material components ? I guess it could mean that too. They sure make it confusing.....