FormerlyHemlock
Hero
RE: Medusas, I don't know what "class-replacement aspects are," but as long as you're not saying that those abilities are worthless to 10th+ level characters and should be free, I'm good. It sounds like you're saying that a Medusa loses some class features to compensate.
I don't see Perytons and Fire Elementals and Mephits and Tyrannosaurs sitting the campfire at night talking about monster lore, so as far as I'm concerned there would be monsters that don't know to avert their gaze, but okay, whatever. You're probably thinking about high-end monsters like beholders and liches, and those guys are smart enough that I'd give them the same advantages I'd give to PCs, which probably means "you automatically recognize this thing as a Medusa by its snake hair (unless it's disguised via Disguise Self) and know that bad things happen if you look directly at it". [It just occurred to me: disguising yourself as a Medusa is a terrific use of a Disguise Self spell.]
RE: dragons again. Here's the thing about dragons: for the most part, they don't have anything good to do with their bonus action, or usually even their reaction, so the Shield/Misty Step/Expeditious Retreat is pure gravy from an action economy perspective. I don't think you're correct about Shield being useful only when fleeing. An adult dragon's damage output is about 100 points of damage per round, so three or four rounds of taking half damage from the Sorlock is at least 200 extra points of damage. Has nothing to do with fleeing except that it delays the point at which you would need to flee. Misty Step is much more situational, but useful for escaping Webs and grapples, or dumping a melee fighter off your back if he mounted you per DMG rules. Not that the dragon couldn't do that anyway, but with Misty Step he can do it with a bonus action instead of an action, and save the action for breathing 91 points of fire all over a clump of enemies.
Concentration requirement on Expeditious Retreat isn't a real cost for a dragon with 2 wizard levels (since there's no opportunity cost in the form of other Concentration spells he'd rather have up). Yes, a PC can hit the dragon and break Expeditious Retreat if the dragon rolls a 1 on his Con save (I believe adult reds are +16 to Con saves), and if so, the dragon now has to spend another spell slot and a bonus action to re-establish the spell. (Or just not even bother to re-cast it, if he's already closed with the party.) Having to re-cast the spell reduces the number of Shield spells the dragon will be casting this combat, but other than that, Concentration is basically a non-issue.
Ah, but here's the thing: if there are 18 crummy spells that don't matter, and 2 spells that make a dragon wizard 30% more dangerous, and the dragon (like other wizards) gets to choose its spells freely... then it's invalid to conclude that 2 levels of wizard don't make the dragon more dangerous, because wizards don't pick the worst options, they pick the best. The DMG is wrongheaded on this one.
I don't see Perytons and Fire Elementals and Mephits and Tyrannosaurs sitting the campfire at night talking about monster lore, so as far as I'm concerned there would be monsters that don't know to avert their gaze, but okay, whatever. You're probably thinking about high-end monsters like beholders and liches, and those guys are smart enough that I'd give them the same advantages I'd give to PCs, which probably means "you automatically recognize this thing as a Medusa by its snake hair (unless it's disguised via Disguise Self) and know that bad things happen if you look directly at it". [It just occurred to me: disguising yourself as a Medusa is a terrific use of a Disguise Self spell.]
RE: dragons again. Here's the thing about dragons: for the most part, they don't have anything good to do with their bonus action, or usually even their reaction, so the Shield/Misty Step/Expeditious Retreat is pure gravy from an action economy perspective. I don't think you're correct about Shield being useful only when fleeing. An adult dragon's damage output is about 100 points of damage per round, so three or four rounds of taking half damage from the Sorlock is at least 200 extra points of damage. Has nothing to do with fleeing except that it delays the point at which you would need to flee. Misty Step is much more situational, but useful for escaping Webs and grapples, or dumping a melee fighter off your back if he mounted you per DMG rules. Not that the dragon couldn't do that anyway, but with Misty Step he can do it with a bonus action instead of an action, and save the action for breathing 91 points of fire all over a clump of enemies.
Concentration requirement on Expeditious Retreat isn't a real cost for a dragon with 2 wizard levels (since there's no opportunity cost in the form of other Concentration spells he'd rather have up). Yes, a PC can hit the dragon and break Expeditious Retreat if the dragon rolls a 1 on his Con save (I believe adult reds are +16 to Con saves), and if so, the dragon now has to spend another spell slot and a bonus action to re-establish the spell. (Or just not even bother to re-cast it, if he's already closed with the party.) Having to re-cast the spell reduces the number of Shield spells the dragon will be casting this combat, but other than that, Concentration is basically a non-issue.
The bulk of these spells seem like they are only useful to the dragon once the dragon has been virtually defeated by the party and is looking to flee for its life.
Ah, but here's the thing: if there are 18 crummy spells that don't matter, and 2 spells that make a dragon wizard 30% more dangerous, and the dragon (like other wizards) gets to choose its spells freely... then it's invalid to conclude that 2 levels of wizard don't make the dragon more dangerous, because wizards don't pick the worst options, they pick the best. The DMG is wrongheaded on this one.