The brain is a remarkable device. With training, it is capable of processing and accumulating a practically unlimited number of skills.
In video games, this can be hard to simulate. (See also Theme Deck.)
Either the controls of the game make it impractical to have access to more than a certain number of moves at a time, or having too large a selection of skills at one's disposal would simply make the game too easy. As a result, characters are forced to rely on a strictly limited move set, rather than being allowed to draw upon all the skills they have learned at any time.
Implementations vary. In some games, the player is forced to more or less permanently forget old skills to learn new ones. In others, the skills are simply put away and may be "installed" and "uninstalled" at will as if they were computer programs. In yet others, they may be assigned to different "stances/states".
Compare Limited Loadout and Mutually Exclusive Power Ups, where your character's limits are defined by the amount of equipment they can carry on their person. In those cases, they still know how to use said equipment even when they don't have it; with a Limited Move Arsenal, they may still have the equipment, but have somehow forgotten how to use it.
Job System has a high amount of overlap, as that's about characters picking and choosing between classes and even skills and is meant to change between them at some points, so changing the arsenal of this trope.
- The Star Ocean games only allow a limited number of attack skills to be assigned to a character, but they can be changed mid-battle. Casters, on the other hand, can access their full repertoire from the menu, but in the third and fourth games, can also assign a limited number of spells to shortcuts where they can be used in combos for a damage boost.
- The Tales games, starting with Phantasia, have the main character equip four skills to use in battle among the dozens of techniques they learn. With the Combo Command item, they can use any of these by inputting a series of fighting game-style commands. Some of the games have late-game items that can double the number of attacks you can equip at a time, with the second set being available by holding down a button.
- In Tales of Symphonia, most moves/spells come in pairs and you can only know one of them at a time (for example, Genis's Thunder Blade and Spark Wave) depending on you exsphere configuration. (barring glitches).
- The first two Paper Mario games. You can only equip a limited amount of badges. You can increase the amount with level up bonuses. The first one had a cap of 30 badge points, while the second has a cap of 99.
- Final Fantasy Tactics, Final Fantasy Tactics Advance, and Final Fantasy Tactics A2. Each job has a set ability, and you can set a second ability (either items or another job's set ability), a reactive ability, and a passive ability. Alchemists can equip both Items and a second job set, though the Items are locked in place and can't be exchanged for a third job set.
- Legend of Mana, with separate pools for combat maneuvers and special attacks.
- Final Fantasy does this a lot.
- I and III had limited spell slots (III also restricting things based on Job).
- Final Fantasy V, with a system that probably formed the basis for the one in Final Fantasy Tactics.
- VIII has limited command and passive slots (the abilities themselves gained from summons).
- X-2 only lets you use the abilities of any one dresssphere at a time (with the ones you can switch to limited by plate you equip). Yeah, this is kind of Final Fantasy's Characteristic Trope.
- Final Fantasy IX, with regards to passive skills.
- Then again, some of the games in the franchise avert this trope completely. Final Fantasy X and Final Fantasy XII allow every character to learn and equip every skill (with few exceptions), though X does allow one to equip only four weapon abilities each for offense and defense.
- VII plays it straight at first, as you only have so many slots for Materia in your equipment. But late in the game when you have access to Master Materia you can easily have (nearly) every skill in the game on every character.
- Diablo series:
- The first game forces anything that isn't swinging your weapon into the Right-Mouse-Button spell slot. Particularly annoying if you're playing a Sorcerer with a dozen spells to switch between. Carrying a staff with spell charges? That takes up the Spell slot too, even though you probably don't want to use it to hit people. You can hotkey up to 4 skills on the Funtion keys, but you still need to 'click' to actually use them.
- The second game is a bit more lenient, as you can map most non-Passive skills to both the Left-Mouse-Button and RMB. And can hotkey up to 16 skills (with the expansion).
- The third game by default only lets you map certain skills to LMB, RMB, and 1-4 keys, and you're limited to one skill per category. This can be disabled in the options Menu, leaving you with the freedom to bind any skill to any of your six buttons. With the only limitation being that certain skills can't be mapped on LMB.
- In Guild Wars, your skill inventory contains what you've learned of the average of 90 skills of your primary and secondary professions that you've bought, plus what you've captured of the ~25 elite skills for each profession, plus up to ~50 reputation-based Player Versus Environment only skills. And to make your choices larger, you can learn to change your secondary profession at will. You can equip: eight skills. Including only one elite and no more than three Player Versus Environment.
- Guild Wars 2 expands this to 10 skills. Slots 1-5 are automatically set depending on which weapon/weapons you have equipped. Slot 6 is a heal spell (3-4 options). Slots 7-9 are regular skills that can be learned with skill points (20-25 options). Slot 10 is an elite skill that requires many more skill points to learn (3-4 options)
- Devil Survivor for humans limits the human character to a set number of spells/skills and support abilities, and you can only have one of any given ability between all of them.
- Breath of Fire: Dragon Quarter has 3 skills for each of 3 levels. Fewer on some weapons.
- Eternal Sonata initially limits you to having one active special move in light and one in shadow. Later, the limit is increased to two of both.
- In Infinite Undiscovery, battle skills are limited to two slots, even for the (friendly) AI characters who are not restricted by the lack of controller buttons. Magic spells are not limited.
- God Hand gives the player a limited number of slots for Gene's moves. It can be increased by purchasing Items from the shop.
- Devil May Cry 3 allows Dante to use one of six Styles, sets of secondary actions used with the Circle button, including extra moves with his melee weapons or guns, evasive maneuvers, the ability to parry attacks and release the built-up energy, summoning a phantom that a second player can control, or slowing down time for everything but himself. The problem is that only one of these Styles can be used at a time, and you can only switch Styles at a pedestal where you use Orbs to buy items. DMC4 added the ability to switch Styles on the fly when playing as Dante.
- Immortals in Lost Odyssey can learn every skill in the game (except enemy-only skills), but can only use a limited number at a time, depending on the amount of "slot seeds" they've used and a few skills that give extra slots. The maximum number of skills the game allows per immortal is 30, but unless you want to end up with a severely unbalanced party due to using all the Slot Seeds on a single immortal, you're most likely to end up with 28 or 29 useable slots per character due to the need to equip skills that increase the number of available slots, although you can still give them up to 3 accessories on top of that.
- Dubloon lets each of your characters use only 4 spells in battle.
- Valkyrie Profile and its sequels. While the particular mechanics were different in each game, you could only equip a limited number of skills at once, although each character could potentially learn every non-weapon skill and each skill related to weapons that they could equip.
- In Epic Battle Fantasy, characters have both moves unique to them and others that are available to all but can only be given to one character. As of 4, you can have a character forget a common move so another can learn it.
- Every Pokémon game, including most of the spin-offs, limits each of your Pokémon to four moves at a time. Whenever one of them already has four moves and is preparing to learn another, you have to choose which move your Pokémon should forget, or just cancel learning the move. "Four Move Slot Syndrome" is the term used by competitive players when a Pokémon has an enormous selection of useful moves for support and/or type coverage, but this trope forces the player to sacrifice one part of its kit. It was considered during the development of Pokémon Ruby and Sapphire to increase the number of moves, but the limit was maintained for the purpose of competitive balance: the more moves a Pokémon has available, the more roles it can potentially fulfill, but the four-move limit prevents any one 'mon from being too versatile in combat. It also adds another layer of depth, as with a large enough movepool, two Pokémon of the same species and level can function differently from each other, keeping the opponent guessing on how to deal with it with it being too overwhelming.
- This is parodied in the webcomic Manly Guys Doing Manly Things with Mr. Fish the Gyarados. His four moves are Shake, Roll Over, Fetch, and Don't Eat Jared. He forgets Shake to learn Hyper Beam.
- Pokémon GO goes even further, limiting each 'mon to only two moves. One must be "charged" by repeatedly using the other, making them effectively a single attack with an irregular damage rate. A later update allowed you to spend a bundle of candy and stardust to unlock a second charge attack, though this comes from the same (usually) small pool of possible attacks as the first one. The Pokémon Rumble games also stick to a two-move limit (though they at least allow every Pokémon to access their entire movepools from the main games), while Pokémon Conquest allows each Pokémon species to possess only one pre-decided move.
- You can only have 20 skills on any given character or item in Phantom Brave. To learn more, you need to have a Witch remove older ones beforehand.
- Shin Megami Tensei:
- In most cases, the Player Character and each of their demons can only know a limited number of skills, and both active and passive skills have to compete for those slots. Upgrades often make it possible to increase the max number of skills available, up to eight.
- Digital Devil Saga allows each character in your party to know up to eight skills at any one time, however outside of combat they can hot-swap those skills with any ones they've learned. It helps, as DDS deviates from the Mons formula of most games in lieu of having a fixed pool of characters.
- In Devil Survivor, each Demon Tamer and demon can have up to three active skills and three passive skills at any one time; the former can swap around their skills when not in a battle. Demon Tamers can additionally equip one Auto skill, while demons have Racial skills that cannot be changed or removed.
- You were limited to 64 skills per character in Breath of Fire III. Not only that, but you could only have one copy of a skill on one person at a time, and you had to use a rather rare item (which could thankfully be farmed) to transfer skills.
- Final Fantasy II limits each character's magic spells to a certain number.
- The SD Gundam G Generation series limited mecha to four attacks until G Generation Spirits, which upped the number to six.
- Eien no Aselia limits each character to three attack skills, three defense skills, and three support skills, each with a limited number of uses between resting. Characters almost always fight in trios, splitting up the roles of attacker, defender and supporter, so that each character only activates one of their skills per encounter.
- In Last Scenario, each character that joins your party can initially equip only 2 spellcards, but key tablets that can be found can unlock their three other slots, allowing up to 10 spells.
- In Magic: The Gathering, there are five colors of magic, and each one represents a philosophy or ideology and thus specializes in particular things. While it is possible to run a deck with all five colors, the result is Cool, but Inefficient, as the colors of mana you have on table will rarely match the color of the spells you have in hand. Until you get used to the metagame, it's much wiser to run decks of two colors or even one.
- Almost any CCG without a maximum limit to deck size will be technically averting this, though. The laws of statistics encourage you towards this trope, but however poor a strategic choice it may be to do so there's nothing actually illegal about throwing a thousand or so unique cards into a single deck.
- Invoker from Dota 2 is an incredibly versatile hero thanks to his ability to combine his standard abilities into new ones, possessing a whopping 11 active skills, surpassing the 4 skills that almost every other hero has. However, he can only store two at a time, and is restricted from invoking new abilities whenever he wants due to cooldown and mana cost. While this restriction diminishes as he gains levels, having and invoking the right spells at the right time and remembering the combination for his spell is key to playing Invoker successfully.
- Darkest Dungeon heroes can only have four battle skills and four campfire respite skills available at any given time. You can only swap them outside of combat or camping.
- Each party member in Cosmic Star Heroine can only use 7 of all the skills they learn, with the eighth slot reserved for an ability that recharges them (and also likely reduces incoming damage until the next turn).
- Mutant Year Zero: Road to Eden: Characters develop mutant powers throughout the game. At any one time they can only have one Major, one Minor and one Passive mutation active, but you can choose which ones are active any time that you are not in combat.
- Armory & Machine initially gives you only one skill slot to use in battle. You can unlock the other five by using keys obtained from defeating bosses, giving you up to a maximum of 6 skills. You are capable of equipping different skills to each slot for use in combat.
- In a non-video game example, From Muddy Waters has Izuku and his Quirk, All For One. He has dozens of Quirks at his disposal, but he can only equip up to three different Quirks at a time and is further limited by his insistence on only using physical Quirks to hide the true nature of his powers. He can get around this limit by stacking multiple copies of the same Quirk, allowing him to greatly increase that one Quirk's effectiveness.
- VG Cats: Parodied in an RPG-Mechanics Verse strip where Leo is limited to four moves, à la Pokémon, which causes trouble when he needs to go to the bathroom.
Congratulations! Leo forgot "Breathe" and learned "Poop"!
- Dungeons & Dragons: In 5th edition, spellcasters have a limited amount of spells they can prepare every day, with clerics and druids able to reset their spell list every day. This is separate from the number of spell slots, which is the number of spells they can cast in a day.
- Dragon Quest:
- Subverted in Dragon Quest VI, where spells learned as part of one class actually stay learned no matter what class you change to after. This ends up being a perfect illustration of the "too easy" justification for not doing this, as you can end up (after lots of grinding) with physical powerhouses who keep healing and reviving each other, or with mages who can simply punch and kick enemies to death.
- Downplayed in Dragon Quest IX: You don't keep spells when changing classes, but you do keep lesser abilities and stat boosts from the class' skill tree.