History Main / AbilityRequiredToProceed

* The exploration gameplay of ''{{Aquaria}}'' is wholly built upon this. You spend most of the game collecting abilities and shapeshift forms that let you explore previously inaccessible areas, most of which are linked to the starting zone. This actually forces your progression into a more or less linear path. For example, near the beginning, you get a telekinesis-like ability, allowing you to explore passages blocked by boulders -- by pulling them away. In some other passages, your path is blocked by currents streaming towards you; you move on to explore them after learning a form in which you can swim against currents

* {{Metroidvania}} games are built on this trope. High jumps (You Must Jump This High To Enter), narrow passages (You Must Be This Small To Enter), and especially the color-coded doors of most {{Metroid}} games.

* Earlier versions of ''NetHack'' had an endgame set in Hell, and if you entered it without Fire Resistance you were instantly burnt to a crisp. (These days, getting anywhere near the endgame without a bucketload of resistances is merely ''mostly'' suicidal.) Somewhat subverted in that there are plenty of ways to get fire resistance before this point.

One way to control the plot of an RPG is to place [[BrokenBridge barriers]] in the hero's path. A destination may be unreachable without access to water transport because the main character has SuperDrowningSkills. You may need to become immune to fire before moving on because the next level is set in a FireAndBrimstoneHell environment. Perhaps you need to enlist the help of a specific NPC, or acquire a specific item, in order to get past the annoying guard.

Sometimes, the item or ability, or skill isn't needed again. But in other cases, it becomes a key part of the main character's inventory, and gets used all the time. Another Example: You can't get to the other island without a ship, so any plot event that happens on the other island can ''assume'' you have a ship. Thus, the game developers suddenly start throwing quests at you that require you to hop back and forth between islands like a bored tourist, and continue to do so for the rest of the game. In extreme cases, the entire game dynamic may change after you obtain this one critical item or ability, because you are now well-equipped/powerful enough to handle challenges that would have been insurmountable before.

See also: ButThouMust. For something that requires you to be at a certain level to proceed before it kills you, see BeefGate. When used carelessly, this can result in {{Cardboard Obstacle}}s. When this is combined with an offensive ability it's a UtilityWeapon.

* Different obstacles in the Dreaming in ''DragonAge'' each require different [[VoluntaryShapeshifting alternate forms]], obtained from lost souls somewhere in the dreamscape. The rat can go through rat holes, the spirit can go through portals, the golem can smash large doors, and the, er, burning corpse can walk through fire.

* Played to some degree in ''TheElderScrolls III: Morrowind'', where You Must Levitate To Enter a Telvanni mage tower. You can find, however, plenty of levitation potions around, you can make your own if you need to, and the main quest also gives you an enchanted item with a Levitate spell burned on it.

* Constantly in ''VideoGame/RadiantHistoria''. Need to defuse magically-hidden bombs? Swap timelines and learn to see invisible things. Need to sneak into a heavily-guarded area unnoticed? Swap timelines and trick a villain into showing off his TeleportSpam so you can [[MegaManning copy it]]. Need to find a way to bypass an enemy's ability to paralyze you? Swap timelines again and talk someone who's beaten him into teaching you how they did it.

* To descend into the deepest parts of the main dungeon in ''{{Ancient Domains of Mystery}}'', the player needs to pass a wall of fire blocking the down staircase, which requires an artifact called the Chaos Orb of Elemental Fire that is also required in the endgame. And it's just as well that the wall forces the player to [[strike: be that tall]] get the Orb, because otherwise no sane person would enter the Tower of Eternal Flames where the Orb, massive equipment destruction, and rapid immolation for the newbie player resides.

This is a subtrope of BrokenBridge. While Broken Bridges railroad you to the plot by requiring that you complete certain tasks before new areas open up, this trope is about railroading you to the plot by requiring that you have the necessary skills and abilities to move forward and open up new areas. This trope is a staple of the MetroidVania genre of video games, though it shows up in other genres as well.

* In ''BeyondGoodAndEvil'' there are locked doors and other obstacles that require a certain tool (or hovercraft equipment, or sidekick) to overcome.

* Certain {{Metroidvania}}-style games have areas that must be entered by double-jumping. Usually, those areas are full of ledges (and {{Bottomless Pit}}s) that can only be travelled by double-jumping.

* ''Franchise/{{Castlevania}}'' games generally tend to give you the double jump fairly early - you'll need it constantly for the rest of the game. However, many of the upgrades are also used only once or twice.

* This happens all the time in various ResidentEvil games, often with either a crank or valve handle.

* In the ''DragonBall Z Legacy of Goku 2'' and ''Buu's Fury'' games for the GameBoyAdvance, certain areas can only be entered by certain characters having reached certain levels. This is evidenced by the number they must be at, bearing a color associated with the proper character (blue for Vegeta, green for Piccolo, orange for Goku, etc.).

* ''{{Castlevania}}'' games generally tend to give you the double jump fairly early - you'll need it constantly for the rest of the game. However, many of the upgrades are also used only once or twice.

* In ''VideoGame/TheLegendOfZeldaOcarinaOfTime'', there are several items without which you cannot proceed. For example, you can't get into the Forest Temple without a Hookshot. As soon as you get inside the Forest Temple, and for the rest of the game thereafter, you will see Hookshot targets ''all over the place''. Many important puzzles are insoluble without the Hookshot. Good thing you never ran into one of those as a kid, before you got the Hookshot, huh? Let's not forget that You Must Be This Tall To Wield The Master Sword...[[PlotRelevantAgeUp Literally]].
** And as a series hallmark, every dungeon in the series will have puzzles that can't be solved without the item found in the respective dungeon.
** It's worth mentioning that in the original ''VideoGame/TheLegendOfZelda'', Link needed a minimum number of [[HeartContainer Heart Containers]] to get the stronger swords.
** In ''VideoGame/TheLegendOfZeldaALinkToThePast'', rocks, stakes, and similar barriers exist all over the world. Most dungeons require you to use the treasure to pass some puzzle or barrier within it. And of course swimming skills are required to visit places all over the series.
** Let's just call this like it is - the entire Zelda series is ''littered'' with this.
** ''Nearly every single boss'' is an example of this trope in the ''Zelda'' series. Any time you find a new item in a dungeon that could ''possibly'' be used in combat, expect to use it against that dungeon's boss.

* ''HalfLife 2: Episode One'' used this relatively early. To make sure you have a gun, the door has a padlock just out of reach. Mainly done to ensure people picked up the gun right by the door, since it is a bit dark in there, and it could go unseen. The commentary reveals that the dev team calls this a "gate".

* In each of the ''Franchise/{{Pokemon}}'' games, there are certain cities and localities you can only reach once you have a Pokémon that knows the move Surf...and once you have the Gym badge that allows you to use it outside of battle.
** {{Fridge Logic}} prevails when you wonder, for example, how Blaine (who was born on Cinnabar Island) ever managed to leave.
** The HM moves in general qualify for this, though Surf is the most obvious. While the other HM moves ''usually'' are only needed to get extra items and such, occasionally you do need them to reach plot-specific areas, Cut and Rock Smash being the two main offenders after Surf.

* ''PhantasyStar [[PhantasyStarIII III]]'' makes use of caverns to transport your party between various worlds. To keep you from [[SequenceBreaking advancing too far too soon]], several of them are locked and require specific gemstones to enter; you acquire those either from InexplicableTreasureChests or from recruited party members.

* Applies not to you, but to your minions, in ''{{Overlord}}''. Can't pass fire without red minions, or poison without green ones! You can go through water, but only blue minions can safely follow you, and if there's a gate-opening wheel on the other side you're just too lazy to turn it yourself.

* To descend into the deepest parts of the main dungeon in ''Ancient Domains of Mystery'', the player needs to pass a wall of fire blocking the down staircase, which requires an artifact called the Chaos Orb of Elemental Fire that is also required in the endgame. And it's just as well that the wall forces the player to [[strike: be that tall]] get the Orb, because otherwise no sane person would enter the Tower of Eternal Flames where the Orb, massive equipment destruction, and rapid immolation for the newbie player resides.

See also: ButThouMust. For something that requires you to be at a certain level to proceed before it kills you, see BeefGate. When used carelessly, this can result in {{Cardboard Obstacle}}s.

* ''PhantasyStar [[PhantasyStarIII III]]'' makes use of caverns to transport your party between various worlds. To keep you from advancing too far too soon, several of them are locked and require specific gemstones to enter; you acquire those either from InexplicableTreasureChests or from recruited party members.

** Sounds suspiciously identical to {{Pikmin}}.

** {{Fridge Logic}} prevails when you wonder, for example, how exactly anyone from Cinnabar Island ever leaves and how Blaine (who was born on the island) ever managed to leave.

Sometimes, the item or ability or whatever isn't needed again. But in other cases, it becomes a key part of the main character's inventory, and gets used all the time. When this happens, the rest of the game effectively has a You Must Be This Tall to Enter sign attached to it.

In real life, these signs are used on amusement park rides and suchlike, because it's easier to design safety restraints for a ride if you know everyone on the ride is big enough to wear them safely. Almost everything else about the riders is irrelevant, as long as they are tall enough.

In many games, something similar happens. You can't get to the other island without a ship, so any plot event that happens on the other island can ''assume'' you have a ship. Thus, the game developers suddenly start throwing quests at you that require you to hop back and forth between islands like a bored tourist, and continue to do so for the rest of the game. In extreme cases, the entire game dynamic may change after you obtain this one critical item or ability, because you are now well-equipped/powerful enough to handle challenges that would have been insurmountable before.

See also: BrokenBridge, ButThouMust. For something that requires you to be at a certain level to proceed before it kills you, see BeefGate. When used carelessly, this can result in {{Cardboard Obstacle}}s.

* In ''VideoGame/TheLegendOfZeldaOcarinaOfTime'', there are several items that act as YouMustBeThisTallToEnter signs. For example, you can't get into the Forest Temple without a Hookshot. As soon as you get inside the Forest Temple, and for the rest of the game thereafter, you will see Hookshot targets ''all over the place''. Many important puzzles are insoluble without the Hookshot. Good thing you never ran into one of those as a kid, before you got the Hookshot, huh? Let's not forget that You Must Be This Tall To Wield The Master Sword...[[PlotRelevantAgeUp Literally]].