Can magic missile be used to propel objects?

Question

Magic missile is a force type and other force types spells typically involve some kind of physical manifestation. See:

• Blade Barrier → force weapons
• Clenched Fist → big, punching hand
• Crushing Hand → big hand squeezing
• Mage’s Sword → force weapon
• Explosive Runes → explosion
• Magic Missile → force projectiles
• Spiritual weapon → force weapon

To factor the amount of push, I was thinking that we could look at the force involved with fall damage. The players handbook states different fall damages as equating to 1d6 damage at given weights.

This chart is from dnd 3.5e PHB on fall damage. $$ \begin{array}{l|r} Distance & Weight \\ \hline 10 & 201 \\ 20 & 101 \\ 30 & 51 \\ 40 & 31 \\ 50 & 11 \\ 60 & 6 \\ 70 & 1 \\ 100 & ? \\ \end{array} $$

That being said, magic missile when empowered is roughly 1d6 + 1 damage after the multiplier is added at 100 ft minimum range. Applying different regressions to the pattern above, we come up with some possible values for the force of incredibly small things such as bullets or pellets. The negatives might make sense for magic missile if you think of it as being a gravity based attack.

These are just mathematic regressions using the fall damage chart.

• Using Quadratic Regression: \$X = -45.784\$
• Using Exponential Regression: \$X = -10.812\$
• Using Logarithmic Regression: \$X = .127\$

A bullet or pellet typically weighs less than .127 pounds. You can look here for example real world weights in pounds.

With that being said, you could fill the chamber of a cannon or gun or even blow dart chamber with potentially anything and have the magic missile burst that shrapnel towards the target. Note that magic missile never misses.

I could understand if the magic missile having a 100% hit doesn't equate to the projectiles having the same, though if the magic missile acts as a continuous pusher, it could apply? The projectiles would be "in the way" of the magic missile which is comprised of force damage.

So, is this actually feasible?

Answer 1

The spell magic missile targets only creatures

A caster can't propel projectiles with the 1st-level Sor/Wiz spell magic missile [evoc] (Player's Handbook 251) anymore than a caster can knock over a statue with a magic missile spell.

The spell magic missile has the entry Targets: Up to five creatures, no two of which can be more than 15 ft. apart. (Also see Aiming a Spell on Target or Targets on PH 175.) That target entry means that if a pile of rocks is between the caster and the magic missile spell's target, and the caster still has line of sight and line of effect to the target, the target is dealt damage by the magic missile spell and the pile of rocks unaffected. On the other hand, if the pile of rocks is big enough that it blocks the caster's line of sight or line of effect to the spell's intended target, the magic missile spell's missile fails. There's simply no third option for the typical caster to have his magic missile spell's missile, for example, topple the pile of rocks then continue toward the target.

In the same way, experimenting with a magic item that has a magic missile effect created behind shrapnel should either see the magic missile effect speed normally toward the designated target yet leave the shrapnel untouched or see the magic missile effect fail because the effect's line of sight or effect or both is blocked.

I'm not trying to be a wet blanket here, by the way. I don't, like, have an agenda that says, "Oho, magic missile! No way, bub!" or anything. The spell magic missile just isn't, technically, the right tool for the job. For example, the 5th-level Sor/Wiz spell telekinesis [trans] (PH 292) is better, as is the 0-level spell launch item [trans] (Spell Compendium 130-1) and the 1st-level Sor/Wiz spell scatterspray [trans] (SpC 180). A player that came to this DM with the idea the question proposes would see this DM recommend one of those spells as the prerequisite for creating a magic cannon instead of the spell magic missile.

"What if the DM says magic missile works anyway?"

If a PC has gone to all the trouble of researching an original magic item that works this way, and the DM has approved the magic item, then that magic item totally works this way, and it doesn't matter if the spell's description or other rules are to the contrary! Original magic items work however the DM says they work, regardless of if the underlying principle is rooted in the game's mechanics. In such a case, have fun blowing up foes—and their fortifications!—with your magic missile-powered cannon!