Okay. So I need to tell you all about my friend and how they blew up a dragon. Pronouns have been changed for privacy.
Some things you need to know about this friend. They are whip smart and an excellent rules lawyer.
Earlier they had asked me if their gnome evocation wizard could manipulate the fireball spell from a necklace of fireballs like they could with their other elemental spells, so as to not hurt their allies. After being stumped, I consult Google and find that spells cast from a magic item are considered to be the same as spells cast from a person. So yes, they could do that.
Fast forward to later in the session, when the stealthing party is busted due to an adult black dragons unfairly high perception roll. There is much cursing. It busts through a stone door a la Kool Aid Man and attacks. First attack nearly takes out the party rogue, who fires back with a shortbow and gives the dragon an unwanted horn piercing. Then the vampire NPC (long story) deals another eight damage, but theyāre still up shit creek at this point.
Now itās my friendās turn. They ask that since the dragon has to make a dexterity saving throw against fireball spells, would it roll with disadvantage if they were standing on it?
āWhat are you doing?ā I ask, completely befuddled. I allow it because I am suitably confused.
Then they cast Misty Step and teleport ONTO THE DRAGONāS BACK. As a bonus action, they smash the necklace of fireballs onto the dragon. Dragon rolls with disadvantage, I roll a fucking NAT ONE. Even with itās bonus, thatās still not enough to meet the DC.
The level of fireball spells on the necklace of fireballs goes up with each bead you throw. So that ended up being 63 d6 fire damage. 63 d6. I made them roll all the dice because Iām not the one that came up with this frankly batshit plan.
It ended up being 187 damage in total. With the prior damage from the rogue and vampire, thatās enough to kill the thing. They take only 5 fall damage, their insane lucky streak continuing.
Then I roll for loot, and guess what magic item pops up? A belt of Storm Giant Strength. Yes, Storm. So now the gnome wizardās strength score is 29 and theyāre stronger and smaller than everyone else in the party, including the Dragonborn. They also took a level in Barbarian, so any monster they meet next is going to crap their pants as a free action.