- conjure woodland beings (and probably other conjure/summon spells like it): At Higher Levels. When you cast this spell using certain higher-level spell slots, you choose one of the summoning options above, and more creatures appear: twice as many with a 6th-level slot and three times as many with an 8th-level slot.
Ok, I'll tackle this one first.
As a 4th-level spell,
conjure woodland beings would be as a 5th level slot in tier 3 (no impact on the spell), but in tier 4 it would be as a 6th-level spell, so yes it would double the number of summoned creatures once you reach 17th level. If you wanted to get three times as many creatures, you would
still have to use an 8th-level spell slot.
- Create undead has some interesting upcast results that might need some thought.
As a 6th-level spell,
create undead would be as a 7th level spell in tier 4. If you wanted to upcast it at 8th or 9th-level, you'd still need to use a higher level spell slot. So, all you'd get "for free" would be one extra ghoul since you can make up to three normally.
- Shadowblade: A hexblade EK (or any gish with multiple attacks) upcasting shadowblade might be an issue depending on the math
As a 2nd-level spell, your damage would
automatically increased.
It would go from 2d8 to 3d8 when you reached 5th level as the spell would upcast for free as if you used a 3rd-level spell slot.
Then it would go from 3d8 to 4d8 when you reached 17th level as the spell slot would be as if you used a 5th-level slot.
2nd-level spells never get upcast for free past 5th level slots, so you'd never get the highest 5d8 damage unless you used an actually 7th or higher level slot.
Spiritual weapon+spirit guardians+cantrips: I'd check the math at a couple points to see how it adds up since it's one of the few stackable spell combos.
Hmm. Not sure what combo this really is, but the individual spells:
spirit guardians is a good spell to start with, so this definitely makes it stellar IMO. Damage begins at 3d8 (using the default 3rd-level slot). It would increase to 4d8 at 11th level and 5d8 at 17th level. A nice boost, certainly, but creatures HP at that point can handle an extra 3 or so damage per round (6 or so at 17th level).
spiritual weapon as a 2nd-level slot improves more, at 5th, 11th, and 17th levels by 1d8 per bump, so a whopping 5d8 at 17th level, but again this is only for one attack per round.
In more dire battles, these spells freely upcast will be strong, no doubt, but at those higher levels utilizing your higher level spells will likely take priority IMO.
Fly adds targets when upcast (so does blind banish & some others like invisibility). Might be worth giving those some thought.
fly as default 3rd-level gets the same bumps at 11th (two targets) and 17th (three targets). Neither will be a big deal at those levels IMO. Useful, very likely, but not huge.
mass suggestion & planar binding dramatically boosts duration when upcast
mass suggestion would get a maximum boost to 10 days. Potentially interesting, but in all likelihood if you aren't screwed by 24 hours of being hit by this spell, I doubt the extra 9 days will screw things up too much.
planar binding gets a bigger potential boost, up to 30 days, but personally I still don't see any issues with it.
Glyph of warding has this footnote in upcasting "If you create a spell glyph, you can store any spell of up to the same level as the slot you use for the glyph of warding." I'd think hard about possible interactions if you allow that with the upcasted slot or the original slot that got expended
Now, this one is
very interesting and a good example! As a 3rd-level spells, it would be bumped to 5th-level maximum at 17th level. I could see some interesting things with that, but by that time even 5th-level spells aren't generally that much more of a deal than the 3rd-level spells.
So, some nice examples, but so far nothing that makes me think this will be too crazy...