Ok so Shadow Monk/Arcane trickster ... Shadow monk can cast darkness, Arcane trickster has fancy mage hand. So here goes...
1) Cast mage hand
2) Get mage hand to pick up rock
3) Cast darkness on rock
4) Have mage hand follow me around the battlefield as bonus action (staying within 30 feet of course). Let say i keep it just behind me so that I'm just outside the darkness raduis
5) Initiate melee or ranged attack against enemy
6) Retreat into darkness**
7) End turn
Enemies turn
1) Enemy can't see me but wants a piece of me
2) Invoke darkness rules
"When you attack a target that you can’t see, you have
disadvantage on the attack roll. This is true whether
you’re guessing the target’s location or you’re targeting
a creature you can hear but not see. If the target isn’t in
the location you targeted, you automatically miss, but
the DM typically just says that the attack missed, not
whether you guessed the target’s location correctly."
3) Enemy tries to guess my location within an area 15 foot radius (around 1 in 25 grid squares by my reckoning)
4) Enemy picks the wrong square coz it doesnt know which square I'm in and as per PHB "you automatically miss"
5) Tell DM. "Sorry. Missed" Stare blankly off into the distance
6) End turn
** I need to keep a personal 15 foot radius grid hidden and mark my location on it to prove to the DM the location I picked within the darkness post attack
Discuss....
AT/warlock probably works better, then you can see through the darkness yourself...
But in practice, it would probably be a big pain for the rest of your party.
jaelis wrote:
I don't think it will be so easy to keep the darkness out of the way.
It means no Martial Arts or FoB attacks
It also means you should have no idea where the bad guys are while you are in darknesss
Beware of readied actions
Likely means you stay safe while rest of party is targetted.
Will likely be in the way/a big hassle for the rest of your party. (yes, I listed it twice)
have fun.
Coredump00 wrote:
Short answer about location known: the rules say that even an invisible creature can be detected if they don't actively hide themselves. It's certainly not guaranteed that the enemies wouldn't know what square you're in, but it's heavily dependent on the DM.
Something that I don't think has been brought up: the reason warlocks are good at this is because they can see in the Darkness. When this monk retreats back into the darkness after attacking, the enemies can just follow them in. Suddenly your own attacks are also at disadvantage, as are those of your allies. It's basically a wash. Manipulating a Darkness'd rock with the Mage Hand is an interesting idea and has application (for example, as a bank robber, or suddenly welching on your deal with the mob), but doesn't sound all that open to abuse.
p3ck wrote:
G
Thanks coredump for the well thought out response. I had not thought of the enemy using the same tactic. Could be some LOLS there 
I would have issue with animal intelligence creatures figuring it out though. Your point about the size of the room, while obvious, is 100% correct also. Finally and also valid point is that, indeed, while inside the darkness I am also oblivious to the outside world but surely it's a simple matter of moving into the light, LOOKING (free action very different from searching) and then moving to target (if within range). I also have the luxury of just moving the hand as a bonus action and BAM I see the light and act normally
Just a heads up the DM will always know where you are, it is up to him to determine if the hostile creature attacked the wrong spot, not you. Thus there is no reason to tell the DM whether or not it missed, he will know. Being in total darkness you will not likely know whether the hostile creature attacked the right spot and missed due to your AC or if it missed due to attacking the wrong spot unless the projectile hits something and makes an obvious sound far away from you.
slumgum wrote:
So let's build a party where everyone has at least 2 levels of warlock and the invocation "devil's sight" is a must...
I had the same idea with the addition of warlock + devil's sight, but I also think this works better for an NPC, maybe
a solo adventurer.
And as they said above, if you can not see in darkness, you don't know what the enemy is doing - not good.
As a DM, I would simply let my monsters / NPCs retreat silently, hide and wait for the darkness to end,
maybe in range to ready an attack at anything that comes out of the darkness.
So if your DM plays at least a little smart, you don't have a big advantage, unless you can see in darkness.