For you gaming ideal, what would each of the following tiers look like according to mechanics and feel (such as superhero or whatever)?
Levels of each tier:
9-12
13-16
17-20
21-24
I think the game is acceptably fine 9-12. There are some 5th and 6th level spells that are questionable, but by and large there isn't anything that bothers me.
The trouble is that non-primary spellcasters characters above level 12 still scale their normal combat abilities, but they do so in generally marginal ways. They still expect to solve problems with attack rolls, damage dice, rider effects, and skill checks.
Meanwhile, spellcasters warp reality. At level 13+, there are spells that allow wholly orthogonal solutions not just to encounters, but to
whole adventures. They solve the game from the character sheet in anti-climactic and undramatic ways. I'm not a fan of essentially every high level spell as presented.
Frankly, I don't think the game wants to or should scale into comic book superhero levels. It's perfectly fine to want to play a game where the characters do that. I don't think it's D&D because non-primary spellcasters don't
and never have. AD&D was built around domain management above name level. In other words, they told you to stop playing D&D. Only video games work in AD&D at high level because video games can limit player choice and force them into basically standard combat. In 3e and 5e both they've found that nobody plays the game at high level because it's (a) too hard to DM because of the spellcaster, and (b) not fun for non-primary spellcasters. 4e circumvented the issue and took levels 5 to 9 and spread them over 30 levels. I think it's well past time to just admit that high level casters don't fit in the game.
The real problem, is the spells above 6th level. From the PHB's 7th level spells:
- Teleport. Far too potent for far too little cost. If any spell were a poster child for having an expensive material cost, it would be teleport. The lower level transport spells have their own somewhat onerous requirements, so I don't have much problem with them. Teleport is just too good. This effect as presented should never exist.
- Resurrection (and True Resurrection). These probably need to exist, but I don't see much reason for them to not just be ways to cast Raise Dead with more expensive materials. 500gp for every 10 days the creature has been dead is fine. I just don't have a problem with death being a prohibitively expensive barrier to cross. I can't remember a single instance when these spells were necessary to a campaign except when a PC were disintegrated or turned to undead. Making Raise Dead just cost 5 or 10 times more in those cases seems fine. Further, I rather like the idea that you might need to visit the afterlife to communicate with people who died decades or centuries ago. Like... I don't know that I can even count the number of stories where visiting the afterlife is a major quest and story point. I feel like these spells rob the game of that. The more I think about it, I'm not even sure that Raise Dead should be a spell, per se. It should be an open ritual available to any class of sufficient level who knows the process.
- Forcecage. This spell is dumb. It's way too good, and can be used to trivialize almost any high level encounter. And it's a CHA save for what reason? It does have an expensive material cost, but the spell doesn't say it consumes it so it basically doesn't really have an expensive material cost.
- Plane Shift. Honestly, this is probably too high a level. The game does need a way for planar travel to occur, but I'm not convinced it should be a high level spell at all. Again, it feels like the game is robbing the players of something here. I feel like this spell in particular should be a ritual or process available to all PCs above 10th level (like Raise Dead). Yeah, it's magic. But the game shouldn't make all magic the sole purview of a few classes, especially when it's essential magic. It doesn't do that with skills or martial prowess anymore.
- Simulacrum. This spell is dumb. It's primary purpose is abusive to the action economy and class design. I have no problem with a simulacrum being a type of construct that PCs can make, like an advanced homunculus or golem, especially for narrative purposes. It should never work like this spell does. Simulacrum should be an entry in the Monster Manual like golems are, and those entries should describe (roughly or in detail) how they are constructed.
The rest of the 7th level spells are either badly scaling fireballs with novel areas of effect, or spells that effectively replicate magic items, or spells that are so narrow that they basically don't exist.
There are
no 8th level spells that need to exist. All of them from the PHB are either redundant (telepathy, glibness, clone), grossly too effective at solving problems (demiplane, mind blank, clone), or so narrow as to be nearly pointless (tsunami, clone). The only two I can imagine being salvageable are Animal Shapes and Control Weather, both of which could be open rituals or Druid class abilities. The rest of them I wish did not exist.
For 9th level spells, it's the same problem as 8th level. Redundant (astral projection, meteor swarm), grossly too effective (gate, shapechange), or so narrow as to be pointless (imprisonment, weird). There is
one effect worth saving: Wish. Wish should probably be limited to 20th level PCs, and should basically only exist because it's D&D and the wish effect
has to exist in D&D because it's D&D. I'd be perfectly happy with wish being a boon granted by major powers or magic items. The rest of the 9th level spells add
nothing good to the game. They do not need to exist as generally available effects or abilities. Most of them could be made into magic items or open rituals, which then gives the PCs something to quest for if they need that power.
The types of challenges the above spells are built to solve don't exist in the Monster Manual. They don't exist in
any Monster Manual. And the characters that don't have access to those spells have
no means of solving those kinds of problems.
So I would take all the 7th through 9th level spells, with the exceptions noted above, and move them to epic level. They don't belong with the rest of the game. That means Bard, Cleric, Druid, Sorcerer, Warlock, and Wizard need 3 new high level abilities at 13th, 15th, and 17th level. I'm inclined to make them feats or ASIs until I found something better for them to do.
I don't think that's a good design, but I think it's a
better design with a
better starting point than how 5e stands now. I think that makes high level play instantly more accessible for DMs.
Yes, this change does mean the game scales very slowly at higher levels. But it already does for the other classes! Attribute bonuses are uneven. For levels 1-10, most characters will go from +3 to +5 attribute bonus, and +2 to +4 proficiency bonus. +4 over 10 levels. Above level 10 (arguably above level 9), you get just another +2, so it's +2 over 10 levels. The game
doesn't build in magic item bonuses anymore (nor should it) so this is the par. The game already slows down. Non-primary spellcaster already never truly reach tier 4.