Simplified Spellcasting

A lot of the time, Functional Magic is bound by formulas and parameters. To achieve a specific effect, an equally specific action is required. Maybe a long chant is required to cast the spell, maybe you have to draw a circle in the ground, maybe you need to make some sort of gesture or hand sign. These are all potential openings, so you'd better hope Talking Is a Free Action.

Then there are the gifted few who are capable of Simplified Spellcasting. They can simplify the process to produce an immediate effect with little or no Spell Construction. This ability is generally the product of either years of experience, a rare talent, resourcefulness, or learned under very unusual circumstances.

It can add an element of unpredictability by allowing the spell to be cast without Calling Your Attacks. It can also lead to I Am Not Left-Handed, when an opponent assumes that the caster has been neutralized because the usual methods have been suppressed.

This sometimes comes at a price, such as making the spell weaker than it would be with proper Spell Construction, carrying higher risks, or substituting the cost for something else.

Note that if casting spells without any prerequisite is normal in-universe, it does not count as this trope. However, the normal requirements do not have to be completely foregone, merely reduced. Also, this is a Fantasy trope.

Examples of Simplified Spellcasting include:

Anime and Manga

In Bleach, casting a Hadou or Bakudou spell without an incantation is considered a sign of skill, though the spell is also weakened significantly if performed as such. Still, it's useful since the incantations are so absurdly long.
In Fullmetal Alchemist, any alchemist who has attempted human transmutation, seen the Gate of Truth and survived will be able to perform alchemy without a formulaic circle, simply by clapping and touching the subject matter, which they can then reshape freely. Convenient, but it can literally cost them an arm and a leg, or worse.
- Both Roy Mustang and Alex Louis Armstrong have gloves equipped with alchemy circles, and Solf J. Kimblee and Scar have them tattooed directly onto their bodies, allowing them to perform their specialties on the fly. In fact, when Roy gains the actual clapping alchemy ability, it effectively slows him down.
  - It's also indicated that Philosopher's Stones can be used to simplify the formulation process, as seen with Kimblee and Alphonse.
- Father, after absorbing Truth, was able to perform transmutations without moving at all.
Nanoha from Magical Girl Lyrical Nanoha learned to enter Magical Girl mode without going through the full chant on her second try, a feat that astonished Yuuno.
- Reinforce inverts this trope, even adding incantations to spells she copied from others... and also increasing their power exponentially. This leads to an Oh Crap moment when she starts chanting something that's clearly a description of Nanoha's Finishing Move. After Hayate receives Reinforce's powers she uses them similarly.
Negi from Mahou Sensei Negima masterfully uses "delayed spells" by uttering the chant beforehand and activating them later in the battle. He can't have an entire arsenal of spells at the ready constantly, but his ability to chant now and cast later allows him to have his spells ready when he needs them the most.
- Jack Rakan actually inverts this trope by adding unnecessary chants and poses to moves when they're not needed. Why? Because it's cool!
- After deciding to be a Magic Knight Negi focuses on Simplified Spellcasting, and no longer needs to prepare spells in advance. At least for a few simple spells.
- Negi's father Nagi was able to skip over most of the incantation for the Thousand Bolts spell, only saying the final few lines and achieving the full effect. Negi completely outclasses him by the end of the series, though, able to double-layer the Thousand Bolts and absorb both using Magia Erebea just by sneezing. Even if that was a case where he'd prepared before, he does the same thing during his 'graduation' fight with Eva using just ten words.
Haku from Naruto manages to make signs with only one hand, an unheard of skill that proves useful in his fight against Sasuke. Just to emphasize how unique this is, no character since has been seen performing that feat.
- The multi-Shadow Clone Jutsu normally consists of three Zodiac hand signs and one special hand sign. Naruto performs this technique with just one sign.
In Scrapped Princess, usually the more powerful a spell is, the longer and more complicated the vocals needed to cast it become. Raquel, a very powerful sorceress, can skip most of that and cast using a single short sentence that doesn't even have to rhyme.
The Slayers actually lampshades this:

"Darkness beyond twilight, crimson beyond blood that flows... I'll skip the rest. DRAGON SLAVE!!!"

- The point being that a full incantation is needed to use the spell's full power, but the necessary part is only its name. And only a few masters can skip even it, even for low-grade magic (and thus may misrepresent a spell, like Lina did in the first season).

Fan Works

The magical style protagonist Doug Sangnoir teaches to Usagi Tsukino in Drunkard's Walk S -- so that she can access her magical potential outside of the "preprogrammed" attacks she gets as a Magical Girl -- is "Will and Word" as found in The Belgariad (see Literature below), where she simply needs to focus her willpower (and magic) on a desired result and speak a key word to enact her will.

Film

Averted in Army of Darkness when Ash forgets the words that need to be said before picking up the Necronomicon:

Ash: Klaatu Barada N... Necktie... Neckturn... Nickel... It's an "N" word, it's definitely an "N" word! Klaatu... Barada... N... [coughs]
Ash: [pause] Okay... that's it!

Literature

In Chronicles of Amber, most magic is either card-based (for communication/transportation) or incantation based. However, Merlin has a way of "priming" spells for use. He basically gives the incantation, but keeps the spell from resolving, allowing for use later. The spells only have a short shelf-life though, which makes this somewhat Awesome but Impractical. Thus those are reserved for either emergency or fast battle: sorcerers try to quickly overwhelm each other with prepared spells, and if this wasn't enough, the rest of a fight is generally "tapped raw power vs. tapped raw power" endurance contest, as neither side can afford anything complicated while being bludgeoned.
In Discworld the properly preformed Rite of Ashkente (which summons Death into a circle) is ludicrously long and convoluted, so they almost always skip most of it.
- The Rite is in fact a comedic inversion of this; anyone with magic ability can perform the complete rite in five minutes with two bits of wood and a fresh egg. Since wizards are inveterate showoffs to a man they find this fact extremely distasteful, and unless pressed for time will add in lots of pointless chanting and dribbley candles to make themselves feel better.
In Harry Potter, it is considered a sign of talent and experience to be able to cast spells nonverbally. So even if you hit an opponent with a Silencing Charm, you can't feel too safe as long as they have a wand in their hand.
- Averted in that young witches and wizards sometimes use magic accidentally, but it's implied that most forms of controlled magic are impossible without a wand, possibly even to Dumbledore and Voldemort.
  - In the first movie, Dumbledore changed the banners in the Great Hall, and in the third movie he was implied to save Harry from falling to his death without his wand, but these are movie-specific exceptions.
  - Voldemort was able to control his magic to some extent as a kid (he used it to abuse the other kids and explore normally inaccessible caves), but it isn't clear how effective this was.
In Inheritance Cycle, magic is usually cast via the Ancient Language, but a sufficiently trained magic user can cast spells mentally. However, this comes at the cost of control; the caster runs a higher risk of the spell going wrong or backfiring.
Kelley Armstrong's The Otherworld series contains necromancers, who use relics of the dead to invoke their more impressive abilities. In No Humans Involved, Jamie Vegas raises the dead without using such a relic.
In the Elenium (and its sequel series, the Tamuli), magic is usually accomplished through an intricate, ritualistic invocation, including somatic components. This can take a while, and is very hard to do when you're in the middle of a battle - not to mention requiring you to think and talk in at least passingly decent Styric, which is apparently a very, very difficult language. However, there are a few who have found alternate sources of divine power, and they can usually whip up some serious magic just with a quick word or gesture.
- Those that have attained a close, personal relationship with a Styric God are able to simply send a mental plea for help. The god in question still gets annoyed if they "shortcut" too much, and insists that they go through the motions if there's time.
Within Rick Cook's Wiz Biz novels, the protagonist finds a way to employ his programming skills to store and retrieve complex spells using counting daemons.
In the Young Wizards series there are a few spells whose spell circle can be pulled up off the ground, stored away, and then put back down on the ground for later use without having to reconstruct the circle.
- A spell can be almost completely cast and then stored in a wizard's mind, to later be released by saying the last word in the spell. However, only a limited number of spells can be stored this way.
- Nita has a special magical construct which she created under special circumstances, which can hold up to nine completed spells. The construct tangibly manifests as a charm bracelet, with each charm being a stored spell.
In the Belgariad and its related series by David Eddings, there is "The Will and the Word", which is quite simply a process whereby a sorcerer focuses his will on a specific result and then speaks a trigger word to make it happen.

Tabletop Games

In Dungeons and Dragons, spells usually have various components which include verbal (spoken magical words), material (essentially magical substances that are consumed by the spell), somatic (gestures) and the like which are needed to cast them. However, the metamagic feats can allow the "rules" of the spell to be ignored. These feats usually come at the cost of an increase in spell level, requiring the caster to use up his/her more limited high-level slots. The second most common cost is them being usable only a limited number of times per day. Abilities that let one ignore or reduce costs for metamagic (popularly known as metamagic reducers) are infamously broken.
- Metamagic naturally continues in the fork Pathfinder. It's far more careful with metamagic reducers, and only printed a single one option that reduces the metamagic cost of a single low level spell (of the player's choice) by one, but it's still considered to be a very strong choice for some builds.
A Hero System mage can build his spells with "Variable Limitations", letting him change the requirements for spellcasting. The example in the 6th Edition rulebook is a mage who normally chants and gestures to cast a Teleport spell, but when he's captured (and bound) by brigands he changes the spell Limitation and teleports away.
In Mage: The Ascension, this is the measure of a mage's enlightenment. Most mages need some sort of focus, depending on how they learned their magic (anything from tarot to mad science) However, as they advance in power, they learn to skip the rituals more. The most powerful ones can perform Reality Warping by will alone.
3E GURPS Technomancer. Mages start out needing to use words and actions in order to achieve the proper mental state, but experienced casters just need to concentrate.
- As of GURPS 4th edition, magic works like this for all spellcasters. The better their skill, the fewer words and actions are needed. Run-of-the-mill casters need loud words and gestures, optimized casters need only a word or a gesture, and it is possible to cast without words if you are really good.

Video Games

Caster from Fate/stay night, due to her High Speed Divine Language Skill. Rin was able to do this as well, but only because she was using magic jewels with contained high quantities of magic energy; once that source was exhausted, she had to recite her spells.
In Tales of Vesperia, while in Overlimit mode, magic users will simply recite a short generic phase instead of a lengthy incantation and cast the spell almost instantly. Rita, for instance, simply says "Blah blah blah, *insert spell name*!".

Web Comics

In Unsounded, spellcasting generally involves a verbal component. The rare ability to create magic without this verbal component is known as tacit casting. Duane is capable of tacit casting, and is apparently an unusually quick caster.