Magic Missile

One of the many ways Functional Magic varies between settings is what range spells can be cast from. In some stories, if Alice the witch wants to put a curse on Bob, she just has to say the right words and burn the right incenses, and he'll be cursed whether he's right next door, in a different hemisphere, or on the far side of the moon. In other stories, Alice's curse might only work within a certain range (like say, a one kilometer radius) but as long as Bob is within that range he'll be cursed but good.

Then there's this trope. This is where the spells a witch or wizard cast act more or less like bullets: if Alice wants to curse Bob, she's going to have to point her hands or wand at him (or at least be facing in his direction), then, when she says the curse, the magic will actually take a physical form (usually some sort of glowing energy) which will shoot towards Bob. If the curse hits him, he's cursed. However, if Alice's aim is off, or if Bob manages to dodge out of the way, he'll remain safely unenchanted. Whatever the spell hits instead might not be so lucky.

Sometimes characters will turn this trope against spellcasters by holding up a mirror. For some reason, a spell that would turn anything else into grey mush will reflect harmlessly off glass, usually bouncing right back at the person who cast the spell. Kind of the Fantasy version of "I am rubber; you are glue."

Please note that this trope is only about cases where somehow enchanting an object relies upon a spell making contact with it. If Alice creates a fireball and hurls it at Bob, that's not a Magic Missile, since the actual spell was making the fireball in the first place. This trope is where, if Alice casts a spell to turn Bob into a ferret, but Bob ducks out of the way, the man standing behind him will be turned into a ferret instead.

May overlap with Ki Attacks.

Examples of Magic Missile include:

Anime and Manga

Mahou Sensei Negima There is also the Exarmatio type spells, a magical attack for disarming and disrobing a target that, as shown by Yue during the contest in the Ariadne Wizarding School, can be deflected or focused into a tight, piercing beam.
In Fate/stay night Rin has her "Gandr" spell. It was originally a curse to give someone the flu, but Rin powered it up so it's more like a gun being fired. It makes gunshot holes in the walls. It even sounds like a gun.
Magical Girl Lyrical Nanoha has Hayate's Misteltein spell, a Petrify effect delivered through lances of magical energy. Nanoha's Divine Shooter is much closer, and its upgrade Axel Shooter is Macross Missile Massacre.
Kido, in Bleach is another example of this.

Literature

Most spells in Harry Potter work like this. Even Avada Kedavra, the most feared spell in the Wizarding World, a Killing Curse that bypasses all magical defenses, is still useless if the victim ducks out of the way or dives for cover.
At least some offensive abilities (in application, not reader reaction) in the Xanth series function in this manner. Trent in particular encounters problems relating to aim, exacerbated by the fact that in the first book he fights a character whose Anti-Magic forces him to miss, to the point of accidentally polymorphing bacteria in the air into other things.

Live Action Television

In Buffy the Vampire Slayer some spells work like this, while others can be done from across the world. In an early episode Amy's witch mother shot a glowing pink blast at her. True to the trope, Buffy deflected it back with a mirror, and she disappeared. The end of the episode revealed the spell was designed to trap someone inside her own old cheerleading trophy.
Witches in Sabrina the Teenage Witch use this trope, among others.

Tabletop Games

Named for the "Magic Missile" spell from Dungeons and Dragons (which isn't actually an example of this trope, since it's just a blast of "force" rather than a spell effect, and also it homes, so you can't dodge it anyway). A number of spells in the game follow this trope, usually those described as firing a "ray," which require the caster to make a ranged touch attack on their target, meaning they can be dodged by agile targets. If the spell requires "line of effect," it can't hit if there is some sort of obstruction between the spellcaster and the target. Characters from the Forgotten Realms setting frequently call wizards "spellhurlers" for a reason.
- The 4th edition actually changed that. Magic Missile is now handled as every other spell, meaning that the wizard needs to make an attack roll and check to see if he hits. It is the wizards basic attack (it's At Will, so the wizard can cast it as often as he likes, in contrast to the limited-use encounter and daily spells), but it can miss.
- And then a supplement changed it back so you could have either/or. Can you say fan backlash?
3d Edition GURPS ranged curses work like this (the caster specifically needs the Curse Missile spell to make them ranged).
While it's not exclusively magic, the power system of Mutants and Masterminds distinguishes between three ranges (four really, but the fourth is not germane to the topic). Touch is melee range, must be within adjacent squares, possibly further for a longer reach. Ranged has a maximum range and range increment penalties. Perception hits anything you can see. The first two require attack rolls. The last auto-hits. Most attacks are done as Ranged because it's cheaper, it fits in with comic book conventions where you can dodge just about anything, and mechanically it can have higher damage.
By default, spells in Mage: The Awakening affect the target's Pattern, which means that as long as the target is within range (which could be anything from "touch" to "anywhere in the world"), it's going to be affected. However, mages always have the option of turning harmful spells into semi-physical projectiles. This can ignore the target's magic resistance, but obviously gives it a chance to avoid the spell if it's quick enough or has cover.

Video Games

Magikoopas tend to throw around magical geometric figures at Mario. In Super Mario World, if they miss you, they might hit a block instead, turning it into an enemy or a coin. In fact, getting these shots to hit blocks is integral to your progress in some places.
- Also in Super Mario Bros., the wands used by the Koopalings in Super Mario Bros 3 and New Super Mario Bros Wii (apparently at least for the latter). The Magic Wand type item in the original The Legend of Zelda game too.
Xavier's spells in Eternal Champions are projectiles that can be dodged.
Magic Arrow in Castle of the Winds.
The danmaku in Gensokyo is largely composed of nonlethal magic missiles. A few exceptions exist, like Reimu's yin-yang orbs, ofuda, and talismans, as well as Sakuya's and Yumeko's knives (although Yumeko's are said to be SWORDS.)
- More literal example: You can play with Marisa Kirisame in Perfect Cherry Blossom with two sets of signs; her A mode unfocused danmaku is aptly named Magic Missile.
If the Reflect spell is anything to go by, all single-target spells in most titles of Final Fantasy actually take the form of magic missiles, even if they aren't graphically represented as such.
- However, they are in large part shown as classic, very dodgeable magic missiles in both Dissidia and the Kingdom Hearts series. There are some spells that spawn directly over the target, like Bind, but even they can be dodged with sufficient reflexes.

Web Comics

Sluggy Freelance spoofed Harry Potter's use of this trope during the fourth "Torg Potter" storyline.
- Gwynn is more of a "demons and dolls" type of witch though.
Naturally, since it's used in Dungeons and Dragons, it's used in Order of the Stick.
In Drowtales this is the easiest and most common attack for a fae to use. Can be dodged. Seen in action here, together with mana shields and ordinary crossbows.
Subverted in Apple Valley where one of the few spells main character Arthur can successfully perform is called "Tragic Missile". It functions much in the same way the traditional Magic Missile does, except it doesn't fly in a straight course - it arcs around and targets whatever it would be the most traumatic and drama-inducing for it to strike. Despite it being his only quasi-effective offensive spell, it doesn't get used often (for obvious reasons).

Western Animation

The wands of the three Good Fairies in the Disney Animated Canon movie Sleeping Beauty. The best example is when Merryweather is trying to stop Maleficent's raven from warning her of Prince Phillip's escape. She flies after him shooting magical blasts, with the raven dodging all except the last, which petrifies him. On YouTube starting at 7:20.
Shrek 2: The fairy godmother's spell, which was reflected to hit King Harold and the godmother herself.
In Jackie Chan Adventures the Dragon, Pig, and Monkey Talismans function like this.