I'm curious as to what the maximum damage you could potentially do with a single cantrip is.
So far the most I can think of is a Warlock of at least two levels with the Eldritch Blast cantrip and the agonizing blast invocation and a 20 in CHA with a total character level of 17 or higher for 4 beams against a target afflicted by Hex and Hexblade's Curse. Which is a total of 1d10+1d6+8 per beam for a grand total of 96 maximum damage (4d10+4d6+32). Beyond that however, I can't think of anything.
- Preferably contain all setup and the casting of the cantrip in the same turn but if necessary you may have one turn to prepare.
- The damage MUST be done by the cantrip but spells like Hex that don't directly deal damage are ok.
- Don't factor in resistance or vulnerability.
- Since we're talking theoretical maximum damage you can assume any damage dice rolled to have their highest value and that all attacks hit but do not crit.
- You can assume advantage on your attack rolls for the purposes of pricing abilities like the rogue's Sneak Attack.
- The damage must all be from the same source so for example you can't use Grasp of Hadar and Repelling Blast to move the target back and forth through a Wall of Fire or to push the target off of a cliff.
- This is single target damage only.
- This is for a single character by himself with no magic items for him or the target now nor in the past