So what’s really going on with this spell?
While The Raven may have provided the initial inspiration, clearly other influences took the spell in another direction.
First, let’s look at the cartoon. Hank’s energy bow shoots light arrows. Eric’s Shield generates a force field. Let’s keep those in mind as we move on to Tony Bath’s Ancient Wargaming.
In that work, we find rules that tell us that a warrior wearing a mail shirt and carrying a shield cannot be hit by arrows. What is Eric wearing? Here, then, is the inspiration for the immunity to Magic Missiles provided by the Shield spell in D&D. Magic Missiles being initially described as magic arrows.
Next, in 3/3.5e, Magic Missiles acquired the description of force. It has remained so since.
Now, in Xanathar’s Guide to Everything, we have a couple of Ranger spells that grant the ability to deal force damage. This is an important conceptual addition. We also got an official description of Hank’s energy bow in the DVD package as being derived from Magic Missiles.
So, what are we left with?
Although, Magic Missile and Shield may have started life as Magic-User spells, what we see in their development actually should make them Ranger and Paladin spells in 5e.
What is Magic Missile’s gimmick? It never misses and it’s blocked by the Shield spell. This clearly identifies it as a magic arrow. It also identifies Shield as a Paladin spell, as witnessed countless times during the course of the cartoon when Eric hastily casts it. What’s really surprising is that the game doesn’t put them on those lists. What’s nice about this is that it informs the entire history of these spells from the changes in Advanced Dungeons & Dragons through 5th Edition.
So, there you have it. For players interested in having a game more faithful to the inspirational sources, you can find the rules for custom spell lists in the Dungeon Master’s Guide. If that’s too much of a stretch, the Magic Initiate Feat can accomplish the same thing.
As an author, I’m just happy to have traced the spells to their sources. Nothing’s more satisfying than knowing where things came from and why they work the way they do.