Limited-Use Magical Device

Blinky: You can only use it, uh... three times. Well! Now, we know the rules!
Toby: Wait! You just used that thing, like, twice!
Blinky: Well the first was to test its ability and the second, to demonstrate it to all of you.
Jim: Blink, you wasted our shots!

— Trollhunters, "It's About Time"

The limited-serving, Fun Size version of a Spell Book, a Limited Use Magical Device generally contains a single spell or a handful of spells or "uses" of a single spell, that is cast instantly on being activated, after which the item either becomes inert or is destroyed. They most often take the form of a scroll but are not necessarily limited to them.

This is most often seen in Video Games and Tabletop Games using Vancian Magic systems; such an item often bypasses the usual spellcasting requirements such as material components, spell slots, and/or Mana costs, and sometimes even allows non-spellcasters to cast the contained spell.

Compare and contrast Spell Book, which is usually non-consumable and permanently teaches the reader one or more spells. Compare Breakable Weapons for physical weapons with this trait. See also It Only Works Once, a similar trope about a device or a tactic that can only be used one time. Magic Potions can be one such example of a Limited Use Magical Device.

This is not necessarily the same as a magical object that can only be used for one purpose, but there can be some overlap.

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Examples:

Anime & Manga

• In the world of Naruto, people are capable of using single-use Ninja Scrolls to inscribe elemental jutsus onto them for various reasons. This ranges from Water Style, to even Summoning Jutsus. Due to this, a ninja can use an element they normally do not have, provided they have a moment to open and use it.
• The Seven Deadly Sins and the sequel Four Knights of the Apocalypse feature "Incantation Orbs", which are single-use orbs containing a spell. This allows for non-mages to use spells they wouldn't normally be able to cast.

Comic Books

• X-Men: A minor character is a mutant whose power is related to the tattoos he has on his body. Each one grants a power that the tattoo symbolically represents, such as flight from wings or telepathy from lightning bolts on his head (referencing the silver age depiction of Xavier's telepathy). It's revealed that that guy is not a mutant — rather, his tattoo artist is the real mutant and each tattoo he makes saps his willpower until he ends up in a coma attempting to emulate the Phoenix Force.

Fan Works

• Dungeon Keeper Ami: A few:
  • Mixed with Single-Use Shield, the shield charms introduced in "Nero's Spell (Part 1)":
    magical trinkets and consumables- that reminds me..." [...] a ceramic disc with three embossed runes.
    "Here, that's for you. I acquired an extra." Cathy looked at the ceramic amulet resting on her open palm and traced the golden lines with one finger. "Magical? What does it do?"
    "One-use shield charm. Crack it to release the spell. It's meant as an emergency defence.
  • A wand introduced in "Abandon Ship, Part 2":
  "Here, Empress. The simplest of the tools granted to you." Olon produced an unadorned white wand from his bag and offered it to Ami.
  [...]
  "That's a weapon," Olon clarified. "Three shots. Use on dark angels. Wasted on anything stronger. Flashy."
• The "Most Special Spell" from the Triptych Continuum usually comes as one of these, as fleshed out in Anchor Foal II, chapter 9.
  The exposed contents would appear as small squares of doubly-mirrored glass, each about a hoofwidth across. With the unused ones, any reflection caught on the surface would tend to shimmer slightly, and often wound up overlapping with whatever image had been captured on the other side.
  They had twisting spirals of silver wire serving as frames, and a small eyelet indicated the top edge. The squares were meant to be hung from the ceiling. They had been intended to dangle over the cloud nest, and each would have only done so once.

Films — Live-Action

• Münchhausen: Cagliostro gives Baron Munchhausen a ring that will make the wearer invisible... but only once, for ten minutes, after which the magic ring becomes an inert ordinary ring. Munchhausen uses his ring to rescue Isabella from the sultan's harem.

Literature

• Dragon and Damsel: Shed dragon scales have residues of magic in them, enough for a handful of spells to be powered by them. Even humans who don't have any magic of their own can cast spells with them if they know the words to the spell. Bernadette uses a dragon scale to cast two different spells—one that lets her become a shadow, and another that heals Azrael.
• The Dresden Files: In Summer Knight, Mother Winter gives Harry an Unraveling, which can utterly destroy any one enchantment, without restriction. He assumes he'll need it somehow for the ongoing crisis in the Fae Courts, but it's Played for Drama when he realizes he could cure his ex-girlfriend of vampirism instead. He ultimately uses it to de-petrify the kidnapped Summer Lady.
• Jill Kismet: Among Jill's weapons is a "sunsword" that is very good for killing creatures on the nightside, but has to be charged in the sun during the daytime. At the climax of the first book, she manages to drain so much energy out of it killing a hellbreed prince that it's rendered inert for the rest of the series, and she frequently wishes it still worked.
• Tales from Netheredge: A transference orb, used to move or teleport smallish objects, has only a set amount of magical energy sealed inside it.
• Uprooted: The Ultimate Blacksmith Alosha spent a century forging an Absurdly Sharp Blade that can kill whatever it strikes, then shatter. The Big Bad's spirit flees her Meat Puppet before the sword can finish devouring her life, so the heroes have to pursue other options.
• Warbreaker: The Returned are a living version. Each Comes Back Strong from death with supernatural powers and potential to gain more, but the core ability of the Divine Breath animating them is to sacrifice their life to heal any illness or injury in another. Lightsong reflects on the paradox that the same people who worship them as Physical Gods are constantly petitioning them for their glorious death.

Live-Action TV

• In The School Nurse Files, Eun-young can only swing her magical sword and fire her magic BB pistol a limited number of times a day. She can recharge her magic by touching In-pyo.

Tabletop Games

• Ars Magica 5^th Edition Item Crafting allows "charged items" that hold a limited number of "castings" of a spell effect and a preset trigger. In exchange, they're much cheaper to create than permanent enchantments. They were added to the game as a generic alternative to 4^th Edition's Magic Potions.
• Dungeons & Dragons:
  • D&D is the Trope Codifier; its scrolls allow spellcasters to cast the contained spell once without using a spell slot, after which the writing on the scroll is erased and the scroll becomes magically inert. Unlike many later examples, the caster must still be able to cast spells of the proper type (arcane or divine); a Magically Inept Fighter can't use a scroll to cast fireballs.^note Some editions have the Use Magic Device skill, which anyone can use, that can allow faking spellcasting ability long enough to use a scroll, wand, etc. Also, many scrolls contain more than one spell (even the weakest can hold up to three).
  • In early editions of AD&D, magic-users/wizards can only cast spells that they have prepared beforehand by expending a spell slot, not by reading them directly from their spellbooks. However, in the 1st Edition Unearthed Arcana supplement, Gary Gygax changed the official rules to allow magic users to read spells from their spellbooks as if they were scrolls in an emergency situation. Doing so destroys the spell in the spellbook (essentially "unlearning" the spell), has a 1% chance per spell level of destroying the two adjacent spells in the spellbook, and a 1% chance of destroying the whole spellbook.
  • Many magical items such as wands, staffs, and rings have a limited number of "charges", some of which are consumed every time the spell within the item is cast. Once the charges are consumed the item becomes useless. This is downplayed in later editions, where these items can "recharge" and regain a random number of charges overnight, but if all are used up at once have a chance to crumble into dust or otherwise turn inert.
  • In early versions of the game, most magical books (librams, manuals, tomes and so on) could only be read once. Once they had been read and taken effect, they vanished and were never seen again.
  • The game also has potions (and related single-use items like incense) and wands with a fixed number of charges which also fit this trope.
• Numenera has the eponymous artifacts left behind by the precursor civilizations. The most common type of numenera, the cyphers, are one-shot items the game encourages you to expend as an Anti-Hoarding measure. Artifacts, on the other hand, are much more durable, although most have the "Depletion" stat, given in standard dice notation, which means that every time you use an artifact, you have to roll those dice and if the result is below the given threshold, the items go inert and useless.

Video Games

• Baldur's Gate, Icewind Dale, Neverwinter Nights, and pretty much every other D&D video game adaptation in existence replicates the tabletop prototype faithfully, with an added option to copy the spell to a mage character's own spell book instead of casting it (which likewise uses up the scroll).
• Black & White: A God Is You, and you can cast miracles through the power of your villagers' dedicated prayer. Alternatively, you can store and cast single-use miracles scattered across the land in bubble form: some are unique, some are generated at regular intervals from magical pedestals, and some spontaneously congeal out of fireflies. They have the advantage of not requiring prayer and not needing to be a miracle that you already know how to cast.
• Crypt Of The Necrodancer has consumable scrolls, including a Freeze Enemies scroll and a Scroll of Need, which gives you an item that you need.
• Scrolls and pretty much every item in the fantasy board game Culdcept are single-use because they're cards. It's actually a special feature if an item doesn't disappear from your hand after use.
• Diablo series:
  • In the original Diablo all spells are available in one-use scroll form as well as in Spell Book form, which teaches the spell to the reader permanently. The scrolls have lower requirements, making them more usable for the non-mage classes.
  • In Diablo II, each class has a unique repertoire of skills, and only the universal utility spells of Identify and Town Portal are available as single-use, no-requirement scrolls. They can no longer be learned as spells. Up to twenty such scrolls can be bound into a book to take up less inventory space.
  • Averted in Diablo III; as an Anti-Frustration Feature both spells are free to cast, and scrolls are obsolete. The game lampshades this by having them fall out of bookcases in the early part of the game and lie unheeded on the floor.
• Divinity: Original Sin features one-use scrolls that can be used to cast spells not learned yet.
• Dragonstomper had magic items you could gather from Random Encounters, and more you could buy from shops. Each item cast one spell and then disappeared.
• The Elder Scrolls:
  • The spell scrolls ubiquitous throughout the series are a textbook example. They allow for a single, free casting of the contained spell even if the caster would not normally have enough Magicka or a high enough skill level to cast it.
  • Magical "enchanted" items other than scrolls come in three types: constant effect (e.g. an article of clothing that increases maximum magicka when worn), cast on use (e.g. a staff that shoots fireballs), or cast on hit (for weapons such as Flaming Swords). The latter two have a limited number of charges and become inert when they're expended, but may be refilled with soul gems and the Soul Trap spell.
  • The eponymous Elder Scrolls themselves are an aversion, being ridiculously powerful cosmic artifacts that, when they can be (meaningfully) read at all (it takes either years of training or special Lost Technology), do not disappear when used.
    • In a twist on the trope though, while the Elder Scrolls themselves are permanent (perhaps more permanent than anything else in reality), those who train to read them can only do so a limited number of times before the act of doing so leaves them permanently blind. Fortunately, the training gives them a sense of when they're about to reach that point, so they can save their final reading for something suitably important.
• Thematic (i.e not exactly literal) example: in El Sword, Aisha's special gameplay mechanic "Memorize" lets her save up to 3 spells in her "memory slot" so she can instantly use them later. Every time she memorizes a spell, a scroll icon appears above her.
• In the text adventure trilogy Enchanter, spells are learned from scrolls that are copied into one's Spellbook: Copying that spell causes it to vanish.
• In Final Fantasy V and Final Fantasy VI, scrolls can be used exclusively by ninja to cast elemental spells.
  • Magic users equipped with spell rods can also "break" their rod in order to cast a high level magic the rod is associated with well before those spells can be acquired properly. In some cases, these spells will be more powerful than their cast equivalents and can go through boss immunities.
• Fire Emblem:
  • In most entries prior to Fire Emblem Fates, most spellbooks function like any other weapon in that they can only be used for a set amount of times before breaking. There are a few exceptions, though:
    • Fire Emblem Gaiden and its remake, Echoes, exclude weapon durability for physical weapons, but both Black Magic (except Nosferatu) and White Magic drain the caster's HP. The HP drain can be somewhat mitigated through usable self-healing items, heal tiles, and another ally using White Magic on them, but can't be disabled by the player entirely. However, exclusive to Shadows of Valentia, Jedah can cast magic without depleting his HP.
  • Fire Emblem: Three Houses brings back weapon durability, including low durability for spells (except for certain classes that have abilities to grant higher spell uses for specific magic types). Spells can't be replenished in the map once out of uses, but return to their original number of uses after the map is over.
• Gothic has single-use scrolls that can be used with minimal cost in mana and with no training, in contrast to the runes which can be used indefinitely, but use up mana and require having learned the appropriate level in magic. Most scrolls are just a single-use version of runes, but there is a handful of spells (like shapeshifting) that are only available on scrolls.
• Minecraft Dungeons averts this by having every artifact in the game be infinitely reusable, with the only caveat being that you need to wait for its cooldown to expire before the item can be used again.
• In Neopets, you can purchase scrolls for your Neopet that have a magical effect on them or can be used in the Battledome. They are one-use only.
• Path of Exile follows the Diablo II model and has only two types of scrolls, Scroll of Wisdom (Identify) and Portal Scroll, but with a few twists. First, both types serve as Practical Currency, since in-game vendors don't accept gold as payment. Secondly, early-game enemies rarely drop whole Scrolls of Wisdom, so you'll have to put them together from five Scroll Fragments. Lastly, you can skip Portal Scrolls entirely if you find the colorless Portal gem, which takes up one active skill slot but frees up some inventory space.
  • The game has a wide variety of orbs, stones, scraps that can be used to improve, adjust and customize your equipment; upgrading items to magic or rare status, rerolling enchantments, adding enchantments, adding/recoloring/linking skill gem slots, and more. Like the aforementioned scrolls, all are consumed on use, and the game refers to them colloquially as "currency" due to their importance in bartering.
• In Pillars of Eternity, anyone with a high Lore skill can cast spells from scrolls, which is usually a good option if you need an additional caster or want to spam a particular spell without expending the caster's spell slots (since scrolls can be crafted in ridiculous quantities by the endgame). There are also Rites—a special non-craftable, non-purchasable kind of scrolls that boost the entire party's skills for a long period of time.
• Pixel Dungeon (and its mods) contain scrolls that allow you to cast a special non-wand spell once per scroll, allowing you to do everything from damaging your enemies to escaping from them.
• Ragnarok Online:
  • The Sage/Professor class can make scrolls to do elemental works. This is used to mess with a target's element if the Sage/Professor or the party is focused in an element the odd mob isn't.
  • Several monsters drop scrolls which allow anyone to use skills as long as the scrolls last. This has led to priests casting Lightning Bolt or Fire Wall in the fields just to mess with some people.
  • The Rune Knight class (advanced form of Lord Knight) are able to make runestones, which they can then use to cast some unique spells, and they expire afterward.
• Skies of Arcadia:
  • There are single-use crystals that can be used to cast spells the characters don't know yet, and to save on magic afterwards.
  • There are also the magic Box items which can be used to cast a spell 3-5 times before breaking.
• The Chronoscepter in Turok Dinosaur Hunter gets three shots, and then never works again. You spend most of the game collecting the pieces, but it will one shot anything short of the final boss.
• Warcraft III: Scrolls of various types (healing, armor, town portal...) can be bought in shops (higher-level spells or multiple buffs can be found as high-level loot) and are one-use, though it's relatively easy to make a stacking system in custom maps.
• The fantasy games in the Wonder Boy franchise have magic as one-use devices, though boomerang magic mitigates this by not disappearing from your inventory if you manage to catch it.
• World of Warcraft potions and other consumables are, well, consumed upon use, although many can be crafted or bought en masse. However, the original release contained several items only available as one-time quest rewards, making them truly only usable once per character (at least after the patch that made them un-tradeable). Most famously, the "Light of Elune" made a character completely invulnerable to harm for 10 seconds without any other restrictions, enabling all manner of potential one-time heroics - and often leaving the item sitting unused in player banks forever, for want of the "perfect moment".

Webcomics

• Referenced in 8-Bit Theater, which is based on a mix of Final Fantasy and D&D. The "Light Warriors" come across Chancellor Usurper while he's monologuing and he attempts to defend his actions by claiming he was reading from a letter that disappeared like a scroll. To which Black Mage states that scrolls don't disappear, just the writing on them.
• Erfworld: Its scrolls appear to be single use. It's here in the caster's hands, then it's gone.
• Unsounded: Some pymarics are designed with a single "charge" and a trigger condition, like a glass charm that produces a magical construct when broken and a land mine that releases a deadly pressure spike when stepped on. These are limited but reliable, as reusable or always-active pymarics can get buggy from prolonged interaction with the Background Magic Field.

Western Animation

• The Kairosect from Trollhunters is a magical device kept within Gatto's keep that gives the user the ability to freeze time around them. Unfortunately, it only lasts less than an hour at a time and can only be used three times before becoming completely useless.

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