->''Think you're the good guy?\\
Your quest is so right,\\
You can't go left.''
-->-- '''Rob Balder''' as [[Franchise/SuperMarioBros Bowser]], ''[[{{Videogame/Portal}} Still Annoyed -]] [[http://www.youtube.com/watch?v=5MQ9wSfuFPI The Bowser Song]]''

In a video game, RatchetScrolling occurs when the game screen only scrolls in one direction and prevents the player from backtracking.

This is similar to an AutoScrollingLevel, except that the scrolling does not occur by itself, but in response to the player's movement through the level. Like the nature of a [[http://en.wikipedia.org/wiki/Ratchet_%28device%29 mechanical ratchet]], it scrolls forward freely as the player moves, but 'locks' in place and prevents the player from backtracking.

Lesser versions may allow the player some degree of backtracking, but only to a certain distance or recent checkpoints, while the most extreme versions will keep your character near the left edge of the screen, giving them very little room to move around without ratcheting the screen further.

This is often a ClassicVideoGameScrewYou, especially when the screen is ratcheted vertically, where any platforms that disappear even a few pixels off the screen edge may leave {{Bottomless Pit}}s in their wake, in defiance of all logic.

In early video games, Ratchet Scrolling was a way to improve performance. If the player could only scroll in one direction, game objects and enemies could be created when they enter the screen and erased as soon as they scroll out, reducing memory usage. A ForgottenTrope now, but was once common, particularly in {{Platform Game}}s.

Note that the name has nothing to do with a certain [[{{Transformers}} Autobot Medic]] or a [[RatchetAndClank well-armed Lombax]].

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!!Examples:

[[foldercontrol]]

[[folder: Action Game ]]

* ''VideoGame/{{Battletoads}}'' for the GameBoy, NES, etc. However, some levels were free-scrolling.
* Almost all [[BeatEmUp Beat-em-Ups]] and {{Action Game}}s with platforming elements in [[ArcadeGame the arcade]] will do this to you.
* All Nintendo-era ''VideoGame/{{Contra}}'' games featured both varieties of this. Not funny when in a [[RiseToTheChallenge vertical shaft]], and [[BottomlessPit you fell off the platforms]]...
* ''VideoGame/SuperCastlevaniaIV'' has vertical ratchet scrolling, making for a few obnoxious challenges if you jump to an area and it ratchets due to overjumping.
** The older ''Franchise/{{Castlevania}}'' games employed this as well. This gimmick didn't leave until ''VideoGame/CastlevaniaSymphonyOfTheNight''.
* Metal Shark Player's level of ''VideoGame/MegaManX6'', the second section has you ratcheted, in contrast to the rest of the game (note that if taking the "alternate" second section, it will be auto-scrolling instead.)
* ''Kick Master'' doesn't let you go backward; while it's a largely linear game, there are many hidden items that can be missed.
* ''Layla'' for the NES, which can lead to some {{unwinnable}} situations.

[[/folder]]

[[folder: Arcade Game ]]

* The original ''VideoGame/{{Glider}}'' had this.
* Pretty much all ''VideoGame/{{Action 52}}'' side scrollers. Can get you stuck in an {{Unwinnable}} situation, as in ''Dam Busters'' and ''Non Human''.

[[/folder]]

[[folder: Platform Game ]]

* ''Franchise/SuperMarioBros''
** The original ''VideoGame/SuperMarioBros.'', the ''[[VideoGame/SuperMarioBrosTheLostLevels Lost Levels]]'' MissionPackSequel, and ''VideoGame/SuperMarioLand''. The way the levels were compressed required this.
** ''VideoGame/NewSuperMarioBros'' has "Challenge Mode". On side-scrolling levels it enables this, on vertical-scrolling levels it becomes an ''IceClimber'' or ''KidIcarus''-style RiseToTheChallenge.
** The ''Deluxe'' port of the original game lets you backtrack to a certain extent, because the game is pixel-for-pixel and the Game Boy screen is smaller than the NES output screen.
* Usually averted in the ''{{Sonic the Hedgehog}}'' games, but the Master System version of the first game has Bridge Zone Act 2 and Jungle Zone Act 2; the former automatically scrolls right and the latter doesn't scroll down. The latter is thankfully averted in the {{Game Gear}} version.
* ''Syobon Action'' abuses it to [[PlatformHell torment the player]].
* ''[[RenAndStimpy Ren & Stimpy: Space Cadet Adventures]]''
* A ''VideoGame/LittleBigPlanet'' level entitled "When things don't go right, go left" is effectively a basic platformer, apart from the fact you scrolled ''left''.
* The Kaizo Mario inspired level of ''{{Pickory}}'' will only scroll to the right, but you can backtrack up to half a screen. One trap can only be avoided by exploiting the scrolling and the fact that anything that goes off the left side of the screen is destroyed.
* ''VideoGame/AdventureIsland I'' and ''III'' feature this. ''II'' has arbitrary points after which the screen couldn't scroll backwards anymore, but otherwise scrolling is two-directional. ''III'' has two-directional ''vertical'' scrolling and the only time there was two-directional horizontal scrolling was in stage 2-6.
* ''Kid Kool'', obviously modeled on the example of ''Super Mario Bros.'', disallowed going backwards. Its SpiritualSuccessor ''VideoGame/PsychoFox'' followed suit.
* ''VideoGame/KidIcarus'' is notorious for its vertical ratchet scrolling - if you fall (and don't have a feather) you die instantly and have to repeat the level. Even if there was a platform just off the screen. Your little wings are no good for flying. This was removed in the sequel, ''Of Myths and Monsters''.
* [[spoiler:The [[TimedMission escape from Wily's castle]]]] in ''VideoGame/Rockman4MinusInfinity'' uses this, though granted there's no reason for backtracking anyway.
* The platforming stages of ''VideoGame/AlexKidd: High-Tech World''. (Other stages ''require'' backtracking.)
* The ''VideoGame/SuperMarioWorld'' GameMod Hammer Brother Demo 3 has this. Unfortunately, it sucks as a result, because you have to go left or backwards at certain points, making it extremely easy to get stuck at random.
* The level called Kinder Surprise in ''VideoGame/{{Something}}'' uses this particular gimmick. It makes dodging the Kinder Surprise eggs much harder. Also, Mario can take the wrong path at some points, but fortunately the are reset doors available.
[[/folder]]

[[folder: Shoot Em Up ]]

* ''Ninja Commando'' is a ShootEmUp that does this.
* [[GameMaker Shoot 'em up Construction Kit]].

[[/folder]]

[[folder: Simulation Game ]]

* Walking your dog in {{Nintendogs}} does this.

[[/folder]]

[[folder: Pinball ]]

* Done in the VideoMode for Gottlieb's ''Pinball/SuperMarioBros'', which features a simplified ''Super Mario Bros.'' video game.
* The VideoMode for ''Harley Davidson: Third Edition'' has an isometric scrolling road that only goes forward.
* Done in the VideoMode of ''Pinball/DoctorWho'', done similarly to the ''Mario'' example above.

[[/folder]]
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