The Hanged Man said:
If you weaken Magic Missile, there aren't any 1st level damage spells worth taking after 5th level (6th for Sorcerers).
Ironically, I'd use that exact same logic to argue the other direction. That is, a high-level spellcaster shouldn't still be using a 1st-level attack spell at all, even with metamagic, and the fact that MM remains heavily used even at high levels is a clear sign that it's too powerful.
Let's say it again: the spell has NO DRAWBACKS. Its damage is typical for its level. There are almost no ways to prevent the damage, and all of the ways that do exist are specialized (i.e., 95% of your opponents can't cast
shield). No saving throw. Multiple targets OR all on one target, with no chance of hitting friendlies. And, it even works on ethereal targets just fine.
IMC, we have a rule for Sorcerers and Bards that predated the 3.5E spell-swapping: any spell could be "upgraded" into a higher spell in the same chain at the start of a new level, which'd free up the low-level slot. So, you could take Summon Monster I, and then trade up for Summon Monster II (freeing a 1st-level slot), and so on ad infinitum. The assumption was that your "attack" spells would tend to the higher end, and your lower levels would fill up with utility or buffing spells.
So, let's look at MM in that context. What if we made a series of spells:
Magic Dart: 1st level, same as MM but caps at 3 missiles
Magic Arrow: 3rd level, 1d6+2 per missile, caps at 5 missiles
Magic Javelin: 5th level, 1d8+3 per missile, caps at 7 missiles
Magic Spear: 7th level, 1d10+4 per missile, caps at 9 missiles
Magic Ballista: 9th level, 1d12+5 per missile, caps at 11 missiles (at level 21, which means realistically it caps at 10)
In all of these, it'd be 1 missile at caster level 1, 2 at 3, 3 at 5, and so on up to 11 at 21. In general, that means for a Wizard, each new spell kicks in right when the previous one caps out, and would be comparable in damage to an Empowered version of the previous.
Each of these seems okay compared to existing damage spells (I'm just doing this off the top of my head so I'm not too sure on the math), and yet clearly the low-level one won't be used at high levels any more.
