Is this Magnificent Summoning homebrew conjuration spell balanced?

Question

I have been looking at playing a conjuration wizard, but annoyingly the only spells that I am interested in are Unseen Servant and Tenser's Floating Disk neither of which have any real use beyond RP (i.e. no combat effectiveness).

I have been looking at homebrew spells to try and propose to my DM. For ease, I would like one scaling spell that covers enough bases, but doesn't get overpowered. The character would likely start at level 1 and possibly go all the way to level 20, so this spell needs to be balanced for the entire level range. It would be selected in the same way as any other 1st-level spell (creation, level up, found as a scroll, etc.).

The spell below is my attempt:

SeriousBri's Magnificent Summoning

1st-level conjuration

Casting Time: 1 Action
Range: 90 feet
Components: V, S, M (something irrelevant)
Duration: Concentration, up to 1 minute

You call forth a creature or group of creatures to serve you. The caster chooses a single type of aberration, monstrosity, or ooze with a CR of 1/4 or greater that you have either seen before or researched to become aware of, and can summon a number of them with a combined CR of 1 or lower. The summoned creatures appear at a point on the ground within range, and disappear when reduced to 0 hit points or when the spell ends.

The creatures are friendly to you and your companions for the duration. Roll initiative for all the creatures at once and they share a single turn. The creatures obey any verbal commands that you issue to them (no action required by you), and each creature can be issued a unique command. If you don't issue any commands to the creatures, they defend themselves from hostile creatures but otherwise take no actions.

At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the combined challenge rating of the creatures you can summon increases by 1 for each slot level above 1st.

Other than possibly summoning a set of niche creatures (which I would avoid), how balanced is this spell?

A point of clarification is that I intend for the spell to allow summoning groups of creatures, but only when they are all the same - so I could summon 2 gibbering mouthers, but not a gibbering mouther and a black pudding together.

Answer 1

• Conjure Animals: level 3 / 1 action / 1 hour / CR 2
• Conjure Woodland Beings: level 4 / 1 action / 1 hour / CR 2
• Conjure Celestial: level 7 / 1 minute / 1 hour / CR 4 (+1/2)
• Conjure Fey: level 6 / 1 minute / 1 hour / CR 6 (+1)
• Conjure Elemental: level 5 / 1 minute / 1 hour / CR 5 (+1)
• Conjure Minor Elemental: level 4 / 1 minute / 1 hour / CR 2
• Summon Greater Demon: level 4 / 1 action / 1 hour / CR 5 (+1)
• Summon Lesser Demons: level 3 / 1 action / 1 hour / CR 1
• Infernal Calling: level 5 / 1 minute / 1 hour / CR 6 (+1)
• Giant Insect: level 4 / 1 action / 10 min / CR 3

Above are all the currently-existing summoning spells, with level, cast-time, duration, and CR limit - with upcasting specified in parentheses.

From this we can see a couple trends. Fiend summoning does play a bit of an exception, so we'll address that last.

1. 1 hour duration for nearly everything
2. 1 minute cast time for anything above CR 3, and the only spell that gets you CR 3 at 1 action is specifically a Giant Scorpion, not a choice of CR 3 creatures*
3. CR is capped at the level of the spell for high levels (5+), and strictly lower for low levels (4,3)*
4. Minimum level is 3
5. Upcasting increases CR only for high level spells (5+)*

*Fiend summoning carries personal risk, and as such is allowed to break some of these rules - notably with Summon Greater Demon only costing an action for a CR 5 creature, and both Summon Greater Demon and Infernal Calling getting a CR higher than the spell level.

---

Now let's consider Magnificent Summoning in context.

• Magnificent Summoning: level 1 / 1 action / 1 minute / CR 1 (+1)

It is lower level than any existing summoning spell. This is of course your intention, so let's table that for a moment.
It costs only an action. This isn't out of the ordinary, but tends to restrict the power of the summoned creatures considerably.
It only lasts 1 minute. This is a big downside, but it's also a big downside that doesn't really mesh with all the other summoning spells.
It summons a CR 1 creature, and matches the slot level with CR for upcasting. This is powerful. It's traits that we only see in level 5+ spells, plus the 4th level spell that puts you and the party in danger.

All together, this spell is strong. Especially being able to summon CR 1 creatures as a level 1 character - which is significantly better than adding an extra PC to the party at that level.
It matches (through upcasting) the strength of the higher-leveled summoning spells - why bother with any of those if you have this?
It strictly outperforms the lower-leveled summoning spells when equivalently upcasted.
In fact, its only downside is that it only ever lasts for one combat - a downside that is DM-dependant to ever even matter.

This is not a spell I would allow any player of mine to use - it would trivialize low-level encounters, it matches or exceeds the effectiveness of all higher-leveled summoning spells, and it appears to be overpowered-with-a-big-weakness.

Answer 2

I would argue that the spell requires severe balancing. Unlike the other summoning spells, it only requires one action, and while it only lasts one minute, you can effectively cast Conjure Celestial at 9th level:

At Higher Levels. When you cast this spell using a 9th-level spell slot, you summon a celestial of challenge rating 5 or lower.

and Conjure Animals at 5th level:

One beast of challenge rating 2 or lower [...] 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 5th level slot

with the flexibility of a 1st-level spell slot for combat purposes.

The scaling is similar to the 5th level spell Conjure Elemental without the restriction of type and the flexibility to summon as many creatures as the CR split allows so this 1st-level spell essentially is more powerful than any other summoning spell that you will access throughout your character's progression - with the added benefit of basically summoning any creature like a Gate spell without the planar restrictions, and under compulsion as long as the creature is CR 9 or lower.