Leeky Windstaff: You did not actually prepare any sonic energy spells today, did you?
—Order of the Stick, #345
- Magical effects are packaged into distinct spells; each spell has one fixed purpose. A spell that throws a ball of fire at an enemy just throws balls of fire, and generally cannot be "turned down" to light a cigarette, for instance.
- Spells represent a kind of "magic-bomb" which must be prepared in advance of actual use, and each prepared spell can be used only once before needing to be prepared again. Also known as "Fire & Forget magic" or "Utility Belt Magic" (you load it, then have N buttons to press).
- Magicians have a finite capacity of prepared spells which is the de facto measure of their skill and/or power as magicians. A wizard using magic for combat is thus something like a living gun: he must be "loaded" with spells beforehand and can run out of magical "ammunition".
A frequently used fourth rule is a naming convention: Possessives and variations thereof—e.g. Sumpjumper's Incendiary Surprise. In a series of spells that is often the same or slightly varied, e.g. "Bigby's X Hand" (...Fingers, Fist, Grab).
This tends to create the problem that the mage must somehow know which spells will be most useful in the near future. If you are expecting combat, then you aren't going to prepare "talk with animals" that day. If you need to talk with an animal, you are then out of luck unless you wait until the next day. To work around this problem, some writers use a Mana or "spell points" system, where the mage can cast any spells they know at any time, using up some of a fixed pool of energy which then gets replenished later.
The name comes from Jack Vance, writer of exotic Science Fiction and Fantasy. Vancian Magic first appears in his novel Dying Earth. Gary Gygax and his collaborator Dave Arneson subsequently "borrowed" the basic ideas for the magic system of Trope Codifier Dungeons & Dragons.
Anime & Manga
- In Mahou Sensei Negima, Weasel Mascot chamo often shows up to bring up concepts such as magical limits and exertion, which Negi tends to push. Also, many wizards in the series like to subvert the "Magic-bomb" variety of spells by overpreparing them: wizards who chant a spell—depending on its power and complexity—are said to be able to hold said spell for at least 20 seconds, effectively eliminating the weakness of enemies knowing what they're about to be attacked with (RPG-style interruption becomes a full-on plot-point when fighting speedy warriors because of this). For a good example of this in action, see the fight with Takamichi and Rakan, but mainly the former.
- Certain scroll techniques seem to be used this way in Naruto, most frequently paper-bombs.
- Magic: The Gathering, in that the "ammo" is represented by cards—you can only cast a spell if you have a card for it, and each card is used up once its spell is cast. Magic's Vancian-ness comes into play in games more often than you'd think. Let's say you have a Fungusaur (2/2, gets bigger as it takes damage), and you want to Shock (does 2 damage) it to strengthen it. You'll kill it. On the other hand, X-cost spells can be "toned down" by just using less mana. And finally, some spells are nerfed just because the original was too powerful, or because the new spell has more options. Fire, for instance, just does two damage (divided any way you want), whereas its predecessor, Arc Lightning, did three, but Fire gives you the option of Ice, a more expensive form of Twiddle (tap or untap anything).
- Depending on the writer, this can turn up in the books: in one instance, Barrin is mentioned as having prepared only certain spells, though this is probably an attempt to explain one of the game mechanics within the universe.
- As noted above, originated in Jack Vance's The Dying Earth, hence the name of the trope. It was not structured into "levels," and it was possible for anyone to attempt to use it, although with the possibility of backfiring. Spells that killed people instantly (such as The Excellent Prismatic Spray) were quite common and every wizard knew them. Of course, the Dying Earth series was not exactly about people killing each other—they were often too petty and vain to take the simple route to their troubles. It is unclear whether the hundred or so spells still known to most magicians included less-powerful choices compared to the ones we see in the books. We might assume that less-powerful magicians couldn't handle or didn't know the more-powerful spells. We aren't really introduced to a wide selection of them. The Dying Earth represent only a few books and the Vancian Magic system wasn't present in Vance's other works.
- Also used in Roger Zelazny's Amber mythos: Merlin, hero of the later novels, explicitly prepares and "hangs" spells to be used later. However, prepared spells decay over time and must be prepared again even if not used. There, it's a matter of pre-constructed spells allowing more efficiency, and a [properly trained] sorcerer can use magic anywhere on a spectrum from Vancian magic to realtime improvisation with the raw forces of the universe. It's not that a wizard can't come up with a spell in the middle of a battle, it's just that a wizard who comes prepared can spend less time worrying about the most elegant formulation of a spell and more time not getting fried by the opposition. The "hanging" spells take this a little further: if you want to use a highly complicated spell in battle, it saves everyone's time if you've already cast most of the spell in advance.
- In the Discworld, wizards are sometimes shown using this form of magic, and the series takes the third rule to an extreme—for the first two books, Rincewind has one of the eight spells of the Octavo in his head, and it's so powerful that other spells just don't fit (or are too scared to stay). Although once it's ejected, it turns out he still can't learn any useful magic. In addition, spells follow the law of conservation of energy: with few exceptions, a wizard must expend as much energy learning or preparing a spell as it uses to do its task. Therefore, impressive spells could take many lifetimes to prepare and simply aren't worth it. And once a wizard finally finds out how summon nubile virgins, he's way too old to remember why he wanted to do that. This is subverted in a fashion in Sourcery, when a character who is a literal font of magical energy is present, wizards are capable of overriding the usual restrictions of conservation of their own bodies by using the excess energy floating around. This also allows them to perform highly tricky transmogrification of turning people into Newts without the usual floating bag of flesh containing all the parts that are too big to fit. Also, the whole idea of spells taking so much energy to prepare is by now sometimes being passed with "well, it was the least competent wizard in the world claiming that". (This was in GURPS Discworld, probably.)
- Joel Rosenberg's Guardians of the Flame series, which features a set of D&D-playing college students who are transported into an actual D&D world, uses the same trope, though note that D&D is not mentioned by name due to trademark concerns. It's definitely supposed to play like D&D, but he even mushed up some of the mechanics (attributes are rolled with 5d4 (reading 0-3) and class levels are on an alphabetical scale (A to whatever) for example. Importantly, it has rules for going berserk (which D&D of its era never did), which is a plot point. After the first book, Rosenberg sort of moved away from Vancian spell-casting—the next one that features really extensive use of magic by a viewpoint character (the wizard in the first book having given up wizardry to pursue the far mightier power of engineering, which has begun to radically change the nature of the fantasy world in which the heroes are stuck) is the sixth, The Road to Ehvenor, and I don't recall any references to Andy-Andy having to prepare spells, or forgetting them after she casts them. You get the impression Rosenberg didn't much like Vancian magic, or writing in detail about magic in general, given the focus of the books on the warrior and thief-types, and the fact that Andy-Andy also loses her magic at the end of Book Six. In the later books it becomes very clear that magic has a strong tendency to consume the sanity of those who use it -- the more powerful wizards are, the crazier they get. And it's also addictive.
- Witches in Kim Harrison's The Hollows series usually make spells in advance. Spells are made in small batches, and only last for a couple of days before they won't work. And one can only carry as many as one has space for on one's person or in one's handbag, or car, or... More accurately, they prepare spells as potions, making this more Device Magic.
- Used heavily, with well-defined parameters, in Lawrence Watt-Evans' Ethshar. There are many different forms of magic, the Vancian one being Wizardry. This is fire-and-forget, heavily dependent on ritual and materials or foci, uses the naming convention almost universally, and most significantly, structured into levels: spell "orders", a second-order spell being eight to ten times as hard as as a first order spell, and so on. There are at least twelve orders referenced, so small wonder that major wizards use an eternal youth spell so they have studying time. Also subverted in Taking Flight. There two fire-and-forget wizardry systems are introduced, both with severe drawbacks. The first one lets wizard prepare any one (but only one) spell in advance, to be used once at his convenience, with practically zero casting time. Can be useful, as some spells need days to cast. The drawback is, until the spell is used, the wizard cannot do any other wizardry. The second system is a plot point: wizard prepares about a dozen of spells, to instantly cast later as many times as he likes. The drawback? No other wizardry ever for that wizard, except for these spells.
- In Matthew Stover's The Acts of Caine series, spells can be patterned into a variety of items and then used as necessary, essentially creating this effect. As the world is a very Low Fantasy take on the Forgotten Realms, the inspiration is likely a direct one.
- In Diane Duane's Young Wizards series, Kit and Nita often use this method of spellcasting, and even sometimes "pre-load" their spells (i.e., "writing" all but the last word of the spell so that it can be used at a moment's notice.) Of course, Kit and Nita have favorite spells, so presumably it's easier for them to remember those words. And of course, at one point Nita actually carries a utility bracelet of spells.
- In Patricia C. Wrede's Enchanted Forest Chronicles the Society of Wizards has a magic system that is very similar, though not identical, to Vancian Magic. Some of the other magic users in the same world use a similar system; spells must be prepared through ritual beforehand, and cast on the spot through the use of a magic word which is set up during the ritual as a trigger. ("Argelfraster" is the one that shows up over and over.)
- In The Obsidian Trilogy, by Mercedes Lackey and James Mallory, the term "cantrip" refers to a spell of the High Magick that has been prepared in Vancian fashion. High Magick spells are mostly long, complex, and cast all at once, but if a Mage has need to leave his workroom and time to prepare, most of the casting for certain spells can be done in advance.
- The allomancers in Brandon Sanderson's Mistborn are all about this. They only have a set amount of metal reserves to draw from for very specific effects. Once those are used up, they're the same as anyone else.
- It looks like vancian magic, but has more in common with the spell point system - you can use the same magical ability as many times as you want until your metal reserves run out, and only need to drink what is essentially a "mana potion" - a tincture of metal particles - to refill your reserves.
- Mages in the Dragonlance Chronicles, by Margaret Weis and Tracy Hickman, are shown to use this magic. At least once the mage Raistlin has explained that each spell must be read and re-read until it is thoroughly memorized, and that upon being used, is forgotten and must be relearned again. All of the Dragonlance Chronicles are explictly set in a Dungeons & Dragons world.
- The original Dungeons & Dragons rules adopted this form as one that would be relatively simple to implement for a game, that wasn't part of any real-world belief structure and easily balanced. Since then, it has become a bit of a sacred cow in later editions, retained even when the game adapts a licensed property (such as Robert Jordan's The Wheel of Time books) that itself uses a completely different type of magic. And, well, Gary Gygax was a big fan of Vance, so not only D&D obviously was influenced, but its lore contains shout outs to Vance: the evil necromancer turned God named Vecna, said to have been the most powerful mortal wizard ever; also, Robe of Eyes from The Dying Earth. Starting in AD&D, and continuing through 3.Xe and 4e D&D, the game began to allow some flexibility to the Vancian system. Examples are as follows:
- Psionics existing alongside the magic optional used
ManaPsionic Strength Points from the very beginning in AD&D.
- AD&D 2nd Edition rulebooks has enough metamagic spells to compose a (semi-official) "school", allowing more flexibility in using—if not memorizing—spells.
- Spell-point systems of all official products were used only in Netheril setting  and Players Options; plus, of course, House Rules variants—in The Net Wizard's Handbook alone 3 of 6 systems were spellpoint-based.
- In 3rd Edition, a spell's effects can be fine-tuned with "metamagic feats", and sorcerers, a separate class from wizards, don't have to prepare spells (but can only know a very limited number of them).
- 3rd Edition also changed the default in-story explanation from "forget the spell when cast"(as mentioned with Dragonlance Chronicles, also used by Vance himself and mocked by Pratchett) to "finish a nearly completed ritual", more akin to the Amber example.
- The Warlock class, as it appeared in 3.5e's Complete Arcane, was completely non-vancian. Warlocks can cast Invocations at will, an unlimited number of times per day, without penalty. However, unless you go epic or invest in feats, you can only learn 12. In addition, the list of invocations is far smaller than the list of available spells. Oh, and something spooky owns your soul.
- Late into edition 3.5e, "reserve feats" were introduced, which grant non-Vancian abilities to the caster as long as he has not cast a particular Vancian spell yet.
- Many of the late 3.5e variant mechanics, from the Warlock on, were playtests for a new system to appear in 4e. The 3.5e Book of Nine Swords moved Vancian encounter powers onto non-magical characters, and at least 4E arrived which ironically both weakened and strengthened Vancian rules.
- 4th Edition gave characters of every class, magic or not, "at-will powers," similar to the 3.5e Warlock's invocations, that can be used as much as a character wants with no penalty. At the same time, the new edition gave every character class Vancian abilities, from Cleric prayers to Fighter exploits. The encounter power mechanic sort of splits the difference between Vancian powers and at-will one by having the encounter powers only refresh after a brief rest. The game still uses the Daily Power mechanic though; like the other two mechanics, it is used with every class (a point of contention amongst some fans – Fighters and Rangers who forget their best exploits after using them – but one that has been elaborated on and explained as the edition has advanced with new books such as Martial Power 2).
- In addition, 4th Edition has added a ritual system based in Hermetic Magic rather than Vancian, adapting some of the larger and more potent spells from earlier editions into something anybody can use if they take the feat to perform rituals and have the appropriate skill for the ritual (with the exception of Bardic Rituals, which require being a Bard). The irony here is that most of the fourth rule spells of earlier editions, like Tenser's Floating Disk or Bigby's Giant Hand, have been turned into Rituals rather than remaining as Vancian spells amongst one or more of the class powers. This is likely due to Rituals being a broader access, while each class has it's own, personalised power list, rather than drawing from a general exploit, spell, prayer, evocation, discipline, or hex list (corresponding to Martial, Arcane, Divine, Primal, Psionic, and Shadow Power Sources, respectively).
- As a corollary, Psionic powers, previously completely different from the Vancian system and power point based, have now been pulled somewhat closer in. Outside of the Monk's disciplines, the disciplines of the other Psionic classes are a mixture of at-will and daily powers—though the at-wills can be augmented with Power Points for better effects rather than requiring PP to utilise at all. This has made the 3 PP-using Psionic classes (Ardent, Battlemind, Psion) only slightly less Vancian than other 4E classes.
- Slayers d20 adaptation averted this trope and introduced a more flexible (and arguably much more powerful) variant to coincide with the anime and manga on which it was based.
- The Vancian system was completely scrapped for the D20 Star Wars game. Force powers have no limit on uses and are used by making a skill check, though your character does have a limited supply of Force Points you can use to make them more powerful or give yourself bonuses, and the powers themselves pull from the user's Vitality Points.
- Also scrapped for the d20 The Wheel of Time rulebook, in which most weaves can be used at varying power levels to do different things and characters can keep using the Power after they're out of daily weave slots if they don't mind risking headaches, nausea, and severing.
- However, retained for Pathfinder, save for bards and sorcerers of course.
- Psionics existing alongside the magic optional used
- Played with in Warhammer Fantasy Battle: Battle Wizards (and sorcerers, shamans etc.) can have up to four "levels" of magic, each level representing a spell and a die to cast spells with. No normal wizard can then cast each spell they know more than once, so even the most powerful archmage is limited to 4 spells. However this limit refreshes each 'turn' rather than each 'day' as is common in other tabletop systems. Wizards can also opt to have a better chance of casting a given spell by neglecting to cast one or more of their others and using the power thus saved on their big kill-everything-within-fifty-feet spell. Of course this is still Warhammer; using more dice on a spell in this way increases the risk of mis-casting and something horrible happening. It's also worth noting that the "Battle Magic" spells featured are simply the most powerful spells known to those schools of magic, wizards technically know a host of lesser spells as well, but these lesser magics are more the province of roleplaying games than wargames focusing on clashing armies.
- Many such lesser spells show up in Warhammer Fantasy Roleplay, which obeys the first law but not the second and third. Wizards know a certain number of predefined spells, but can use them as often as they dare. In some editions, certain types of magic (mostly necromancy) can bypass these limits.
- GURPS: Thaumatology spends a few pages discussing how to make Vancian magic work with its system. The default magic is based more on Larry Niven than Vance, however, and Thaumatology consists mostly of a toolbox for inventing any magic system you want.
- Slightly subverted, and then averted, in Unknown Armies. Adepts have to have charges to cast spells, but you can use one or more charges for one of a number of different effects (depending on the charge size), and, when all else fails, use it for a Random Magic effect, which is (mostly) determined by the GM. Meanwhile, Avatars don't have any kind of charge system: they just choose to do it, and they do (if they pass the roll, of course).
- TORG mostly uses more Hermetic magic, but in the more magical realms, mages can also learn Imprinted spells, which allows them to do the long prep of a spell beforehand, and then at some point later perform the one gesture final part of the spell to invoke it instantly.
- Rolemaster has a "power points" system. A character has, regardless of profession, power points according to their level, spellcaster professions tend to have good attributes for their respective magic types (intuition for channeling, empathy for essence, presence for mentalism), resulting in more power points than a fighter (although each character has to choose their magic domain when creating the character so that if they decide, for some reason, at some point, to try to learn spells they can't just pull it out of their arses).
- The Swedish RPG Chronopia has Librumages (who stores their spells as pages in giant tomes) as well as the powder based Cranemorts (essentially Vodoo priests) and Witchbarons (who use more standard spells). While both types require quite exotic ingredients to mix the ink/powder as well as much time and energy to prepare their spells, once they're loaded up however, the only real limit to their stored spells is their carrying capacity (and you can bet that they always keep more at home).
- Naturally, Amber Diceless Roleplaying, following its source material, includes "hanging" spells, Vance-style, in its magic systems.
- Unsurprisingly, pretty much every video game based on Dungeons & Dragons.
- With the sole exception of Dungeons and Dragons Online, which uses a Mana Meter. (You still have to prepare spells at a tavern or a rest shrine, however). In addition, potions to restore Mana are rare. Unless you pay for them, that is.
- And Baldurs Gate Dark Alliance I & II for the consoles had an energy meter, rather than loading spells.
- Used extensively in the Touhou series, and handwaved as a form of ritualized magic dueling which allows for balanced fights between skilled humans and beings of godlike power. Note that this only applies to spellcard rules; magic is not inherently Vancian.
- Also part of gameplay in Fighting Games Scarlet Weather Rhapsody and Hisoutensoku, where you prepare a deck consisting of system, skill and spell cards beforehand, and use them during the fight.
- Every technique in Pokémon has a set amount of PP that determines how many times a Pokémon can use it. The only exception is Struggle, the default attack every Pokémon knows but can only use after all other moves have been exhausted, and the user experiences recoil damage when its used. Arguably, this only applies to a Pokemon's battle capabilities, at least if the Pokedex is to be believed: For example, if a Pokemon that is known for being able to power entire cities was held to this trope, rolling blackouts must be painfully frequent. Or the people running the power plants simply use elixirs and/or Pokemon centers to restore PP. The better example is the HM instance. Indeed, even if a Pokemon's PP for an HM move such as Fly is exhausted, it can still be used outside of battle. This is also true, somehow, if the Pokemon has fainted. In the original Japanese, "fainted" was "unable to battle", a phrase that doesn't necessarily imply unconsciousness. They changed the term in the English release because of the character limit.
- The BattleChips in Mega Man Battle Network are a technological version of this. (Fortunately, MegaMan also has a chargeable buster that never runs out—much better backup than a Pokemon's Struggle move. Later games and the Star Force spinoff series introduce alternate forms whose charged shots are often good enough to use in lieu of chips.)
- Magic works just like this in The Magic Candle. Spells are strictly verbal, but once cast, a spell fades immediately from the caster's memory. Wizards prepare for battle by memorizing their spells over and over, apparently compartmentalizing the "copies" somehow.
- Final Fantasy VIII works exactly this like this. Each character has a Magic stock which can contain up to 32 distinct spells with a maximum 100 uses each. But instead of resting, characters gain spell charges by Drawing them from opponents and certain objects, or by using various abilities to extract them from items or upgrade other spells. By contrast, sorceresses can apparently use magic at-will, although the character who becomes a sorceress only does so as a Limit Break (presumably to avoid being a Game Breaker).
- Wizardry 1-5, Final Fantasy, and Final Fantasy III used a system of leveled spells with a number of shots for each level, rising with levels, avoiding the need to memorize specific spells but keeping the essential flavor. The first of each series even had nearly identical spell progressions! The Final Fantasy games added the twist that each character could only learn 3 of the spells available at each level (characters in III could change spells, but they had to overwrite spells they currently knew, making switching magic types expensive).
- Suikoden I used a magic system similar to Final Fantasy I and Final Fantasy III, but it's more restrictive since each character could only have one magic-granting "rune" implanted, so there can only be a single spell chosen from each level. And those that are permanently equipped with a non-spellcasting rune (which enable things like special physical attacks or stat enhancement) can never use magic. This is very much Gameplay And Storyline Segregation, as one particularly powerful mage that you recruit is explicitly stated to have over 100 magic runes implanted in him. As do the other games of the Suikoden series, though they allow a bit more flexibility by allowing two to three "rune slots" instead of just one. This allows most characters the option of casting spells, though some will be bad at it no matter how powerful the rune they're given.
- Chrono Cross uses a system like this. Each character has a set number of rows and columns in which "elements" can be set. Each element can only be used once per battle (except for "consumable" elements, which act like items do in other RPGs). And even consumable elements have a limit of five uses per slot.
- Japanese Roguelike Elona follows this to the letter. Quite unfortunate considering how easy it is to fail most high-end spells, and how rare their books are.
- Similarly, the roguelike Ancient Domains of Mystery uses the same system, Vancian Casting from MP. Somehow, ADOM is somewhat more forgiving than Elona about spells. Some of the best books are extremely rare, but reading an entire spellbook grants hundreds of castings.
- The Enchanter trilogy from Infocom plays this almost completely straight. The spells themselves are very tongue in cheek with "fold dough 13 times", "balance checkbook", and "turn original into triplicate" being several examples. Or, for that matter, "turn purple things invisible".
- There was a book written in the Enchanter universe, which added a few points to the system along reasonable lines. It's possible though difficult to memorize a spell permanently (depending on the spell and caster, this can take months to years of effort), and the enchanter's school mentioned trains every student to 'lock up' Gnusto, which copies a spell from a scroll into a spellbook. Spells can be cast directly from a spellbook rather than memorized, although it means you actually have to read and speak the spell rather than simply release it from your mind. And a spell's exact effects (and appearance written in a spellbook) are dependent on the personality of the caster or the book's owner. The last is used to explain why all the best magic-users tend towards the Bunny Ears Lawyer type.
- The Spellcasting Series, written in part by the same people, does the same thing, and ups the ante by including a spell that transforms other spells. "Enlarge Tree Root" -> "Enlarge Wee Fruit", and so forth.
- The game Balances by Graham Nelson was written as a demonstration of how to write Vancian magic in the Inform programming language, and is explicitly based on the Enchanter series. As befits its status as a demo program and source of code snippets, it takes Vancian magic Up to Eleven—spells can be reversed, work on almost every object and NPC in the game (and fail gracefully when they don't),, and one spell even provides an example of a spell that can only be memorized once.
- In RuneScape, there is an example of this with the magic runes. Each spell takes a certain combination of runes, and if you are out of a required type of runes, you either need to buy more or make them by mining rune essence and taking it to a special altar. In other words, magic flat out requires ammo to be cast. In fact, runes are said to only channel power from somewhere, neither them or the player holds any power within.
- Legend of Dragoon features spells as buyable, boostable combat items. This would be useful, were they not forced to share the same limited inventory space as your healing items. It does have a few reuseable spell items though.
- The panel system in Kingdom Hearts: 358/2 Days works this way. On a grid, you select which items, weapons, abilities, and magic spells you have before you take on a mission. During the mission, you are limited only to the amount of casts that you've set up for your spells.
- Earlier versions of Nethack had a similar system, where reading a spellbook would give you a finite number of uses of the spell. An unofficial patch, later integrated into the main game in version 3.3.0, changed spells to be forgotten after a sufficient amount of time had passed.
- Kings Bounty (the original one). The hero has a finite number of spell slots (determined by class, level, and gained artifacts). Spells can be bought in towns or found as treasure, and to be able to buy spells hero must have free spell slots (when found, spells may go over the limit number, though). Each spell is one-shot.
- In Wandering Hamster, Bob the Hamster, who is a Cute Bruiser Magic Knight, uses this type of magic in the form of his Magic Smite spells.
- In The Sims Medieval, Sim wizards have to prepare spells, but can use them any number of times afterwards unless they deliberately "forget" them (a process that involves smacking themselves on the forehead with their staff). They can't prepare all the spells they know at once, which means they will occasionally have to swap them out.
- Magic in Dark Souls consists of putting spells in attunement slots giving a certain number of uses before needing to rest at the bonfire. And if you find multiple scrolls of the same spell, you can double up on it.
- Alchemy in Mabinogi uses specially prepared crystals, which when "fired" from an alchemy cylinder allow you to create golems, drain life, etc. It also has base elemental crystals, used both in crafting advanced crystals and in basic attacks such as Water Cannon or Flameburst.
- This is how staves and enchantments work in The Elder Scrolls series, though the magical item in question generally has several "uses" before it runs out of energy. Alchemy also works like this. You gather ingredients with different effects throughout your travels, then "prepare" single-use potions (for yourself) or poisons (for enemies) when you're not in the middle of a battle. The effects of said potions and poisons are typically stronger than spells of the same skill level, but are limited by the fact that you can only use them once (and in the case of poisons, on single targets only, rather than groups).