View source for Sonic the Hedgehog 3/Bugs

{{back}}[[Category:Bugs]]
This page documents bugs/glitches that have been found in ''[[Sonic the Hedgehog 3]]'', as well as specifying whether each bug was ever fixed in a subsequent version of the game (''i.e.'' ''[[Sonic 3 & Knuckles]]'').

==General bugs==
===Vertical wrap glitch===
{{bug
| image=Sonic3 MD Bug VerticalWrap1.png
| caption=Duck until the screen scrolls down...
| image2=Sonic3 MD Bug VerticalWrap2.png
| caption2=...then jump, and this happens.
| image3=Sonic3 MD Bug VerticalWrap3.png
| caption3=Easy access into Knuckles' route.
| desc=In Acts where the level wraps vertically, the player can duck, wait for the screen to scroll down, then immediately jump, causing the screen to mistake the player's position and make the screen scroll all the way around. During this time, the player can move through certain objects, including kill planes, allowing access to otherwise restricted areas.

Acts affected:
* [[Marble Garden Zone]] Act 1
* [[IceCap Zone]] Act 1
* [[Sandopolis Zone]] Act 2
* [[Sky Sanctuary Zone]] Act 1
|fixed=''[[Sonic Origins]]''}}

===Knuckles has yellow socks===
{{bug
| image=Sonic3 MD KnucklesSocks.png
| desc=During normal gameplay in ''Sonic the Hedgehog 3'', [[Knuckles the Echidna|Knuckles]] has yellow socks. Development screenshots suggest this was never intended, but some Western artwork erroneously gave Knuckles yellow socks as a result of this issue.

While incorrect, the use of yellow socks is thought to have been a fix for more serious palette errors that can occur if green socks are used. The limited number of colours in the palette means that were the socks green, other elements of the screen would have to turn green, such as the HUD. Knuckles has the correct sock colours in Competition mode and green is used throughout ''Sonic & Knuckles'' (although yellow socks in cutscenes persists as an issue in the Sonic/Tails campaign).
| fixed=''[[Sonic Origins]]''
}}

===Corrupt shield graphics===
{{bug
| image=Sonic3 MD CorruptShields.png
| desc=More often than not, shields will become corrupted for a few frames during screen transitions (e.g. entering a Bonus Stage or finishing Act 2).
| fixed=
}}

==="Blue Knuckles" appears on the signpost===
{{bug
| image=Sonic3 MD BlueKnucklesSignpost.png
| desc=When the [[signpost]] is falling, you can see [[Blue Knuckles]] on the post.
| fixed=''[[Sonic 3 & Knuckles]]'': [[Knuckles the Echidna|Knuckles]] was removed from Sonic and Tails' signposts altogether
}}

===Jump buffering on level load===
{{bug
| image=Sonic3 MD Bug JumpBuffering1.png
| image2=Sonic3 MD Bug JumpBuffering2.png
| desc=It is possible for the player to buffer a jump by holding down a button when the title card appears. This results in the player's character immediately jumping as soon as the player object is loaded. This can be abused in the [[Bonus Stage (Sonic the Hedgehog 3 & Knuckles)|Gumball Machine Bonus Stage]] to either make Sonic transform into [[Super Sonic]] or make Tails fly.
| partialfixed=''[[Sonic 3 & Knuckles]]''. While fixed for all player objects in the main game, it was not fixed for the player objects in Competition Mode
}}

===Move during end-of-level score tally===
{{bug
| image=SonicCanMoveDuringScoreTally.png
| desc=If a human is controlling Tails, it is easy to break certain parts of ''Sonic 3'' by having Sonic be carried by Tails while flying. Catch a lift from Tails as the end-of-Act 1 signpost hits the ground, and Sonic will be able to move around during the score tally.
}}

===Rolling around quarter-pipes and loops===
{{bug
| image=Sonic3 MD HCZLoopStop.png
| caption=A common stopping point in Hydrocity Act 1.
| desc=Loop and ramp collision is wonky in some places in ''Sonic 3'', meaning that when characters are rolling at high speeds around quarter-pipes or loops, they can abruptly stop for seemingly no reason.

This glitch is easy to see in [[Hydrocity Zone]], where players are interacting with ramps and springs, however it also affects areas of [[Carnival Night Zone]] and [[Launch Base Zone]].
}}

===Tails assist with Lightning Shield===
{{bug
| image=Sonic3 MD TailsLightningJump 1.png
| image2=Sonic3 MD TailsLightningJump 2.png
| image3=Sonic3 MD TailsLightningJump 3.png
| caption=Have Tails fly Sonic up there.
| caption2=Double jump.
| caption3=And now you can see things you shouldn't.
| desc=Tails' ability to pick up Sonic causes a myriad of issues in ''Sonic 3''. While the game stops Tails from being able to fly higher than the top level boundary, carrying Sonic up there and letting him double jump with a [[Lightning Shield]] grants him access to parts of the game he shouldn't be allowed to get to.

This exploit is even easier to achieve in ''Sonic 3 & Knuckles'', as [[Hyper Sonic]] has a higher double jump height.
}}

===Tails assist with camera panned upwards===
{{bug
| image=Sonic3 MD TailsCameraObject 1.png
| image2=Sonic3 MD TailsCameraObject 2.png
| image3=Sonic3 MD TailsCameraObject 3.png
| caption=Stand here and look up.
| caption2=Get a lift.
| caption3=Fall down and things break.
| desc=If Sonic is standing on an object, looks up (to pan the camera upwards) and then is picked up by Tails, the camera does not instantly reset. This means the object below can easily be hidden from view and therefore be deactivated. Dropping Sonic can cause him to be wedged inside the object and then pushed to the left or right, potentially into a wall (which in turn opens up the possibility of zipping).

This can be exploited in the first Act of Angel Island Zone, for example, to get Sonic into the Knuckles-only area.
}}

===Insta-Shield upon landing===
{{bug
| image=Sonic3 MD InstaShieldLanding.png
| desc=If Sonic attempts to perform the [[Insta-Shield]] right as he lands on the ground or an object, he will not be able to perform the move on the next jump. The reason for this is because the flag to control Sonic's double-jump ability is set to 1 when the move is initiated, and to 2 when its animation finishes, preventing repeated use of the move in the same jump, with the flag being reset to 0 upon landing. The Insta-Shield animation does not stop when Sonic lands, so if the move's animation ends after Sonic has landed, the flag will be stuck on 2 until Sonic touches the floor again.{{ref|https://s3unlocked.blogspot.com/2019/10/one-steve-shield-limit.html}}
| fixed=''[[Sonic 3 & Knuckles]]'' (the game checks whether the double jump flag has already been cleared before attempting to set it to 2)
}}

===Music selection anomalies===
There are numerous bugs in the way music is played and resumed.
====Odd behaviour when Invincibility or Super wears off during a boss====
{{bug
| image=no
| desc=If [[invincibility]] wears off during a boss, there is no change to the music.

This behaviour dates back to the original ''[[Sonic the Hedgehog (16-bit)|Sonic the Hedgehog]]'', and is still generally the right thing for normal invincibility: the player would have become invincible by collecting an invincibility monitor prior to the boss starting, which would mean the invincibility music was then replaced by the boss music, which should not change when it wears off.

However, it does not account for Super Sonic. If Super status is lost by running out of rings or being smashed by the final Launch Base boss (which may be considered a bug in itself), the invincibility music will continue to play. This also results in the invincibility music continuing throughout Launch Base's ending if the boss was defeated as Super Sonic.

There are also some cases where the boss flag is not set or cleared at the correct time. This is most noticable when defeating the midboss of [[Marble Garden Zone]] as Super Sonic: as the boss flag is never set during this boss, the Act 1 music will restart very briefly as the boss is defeated, due to Super Sonic's invincibility being cancelled. In [[Angel Island Zone]] Act 1, if you are invincible, and you go up to where you meet the Act 1 boss before it engulfs the Zone in flames, but don't trigger the cutscene, the invincibility song keeps playing even after the invincibility wears off. This is caused by the boss flag having been set too early. The only way to stop it is by meeting the boss and continuing with the level.
}}

====Act 2 music in Act 1 after restart====
{{bug
| image=Sonic3 MD Bug Act2MusicInAIZ1.png
| desc=''Sonic the Hedgehog 3'''s seamless Act transitions are written in such a way that the physical level does not need to change over at the exact same point as the logical end of the Act. [[Angel Island Zone]] and [[IceCap Zone]] make use of this; the former's level transition occurs when the island burns, while the latter switches while running through the tunnel out of the cave into daylight.

If the player restarts at a [[Checkpoint]] or after a [[Special Stage (Sonic the Hedgehog 3 & Knuckles)|Special Stage]] in these transitionary areas, the correct Act 1 title card will be shown, but Act 2's music will play. There is one Checkpoint on each route in IceCap where this can occur, and one Checkpoint and a Special Stage in Angel Island. ''[[Sonic 3 & Knuckles]]'' contains a special-case fix for the checkpoint only in Angel Island, but the bug still occurs in all other situations, including at the Special Stage a few pixels away.

| partialfixed=''[[Sonic 3 & Knuckles]]''
}}

====Incorrect boss music plays after avoiding drowning====
{{bug
| image=Hzsubboss.png
| desc=While fighting any boss where water is present, if the player stays underwater long enough to trigger the drowning countdown, and then jumps out of the water, the music for ''Sonic 3 & Knuckles''<nowiki>'</nowiki> mid-boss fights is played instead of the correct track.  This behaviour also seems to date back to ''Sonic 1'', where resuming music after drowning was handled with a lookup table with a single special case for boss areas, rather than using the stored previous track as ''Sonic 3'' does elsewhere.  This bug is much less noticable in ''Sonic 3 & Knuckles'', as the ''Sonic & Knuckles'' midboss music happens to be the correct track to resume during the [[Big Shaker]] fight, which is by far the more likely of the two water bosses to induce drowning.
}}

===Bugs specific to Super Sonic===
Note that [[Super Sonic]] can be involved in other bugs that are specific to certain levels, which are described in the relevant sections below; this section is only for those that span the entire game.

====Rolling causes Super Sonic to slow down====
{{bug
| desc=If playing as Sonic or Sonic and Tails, becoming Super Sonic and rolling will cause the player to slow down.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Super Sonic can bubble-bounce====
{{bug
| desc=Super Sonic can perform the [[Water Shield]] bounce. This is incorrect because Super/Hyper characters are not supposed to, and in all other circumstances do not, gain shields' double-jump powers (although they ''do'' collect and 'store' them and will gain the graphics and power as normal upon exiting their Super/Hyper state).
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Misaligned balancing animation====
{{bug
| image=Sonic3 MD SuperSonicHead.png
| desc=Super Sonic's balancing animation isn't aligned properly, so for some frames, the top part of his head appears two pixels to the right (or left) of his body.
}}

===Glitches specific to the level select/sound test===
Cheating ''via'' the combined level select/sound test screen enables various other glitches.

====Checkpoints are not cleared after returning to the level select====
{{bug
| image=Sonic3 MD Bug LevelSelectCheckpointGlitch.png
| desc=Various glitches are caused by passing a checkpoint in any Zone and then picking another Zone via level select. It causes the title cards to be wrong (referencing the level in which the checkpoint was hit) and Sonic/Tails get spawned in very odd places within the level, including walls, as the checkpoint coordinates do not match a sensible position in the new level. Also, objects sometimes don't load or they don't work properly. 

Selecting [[Angel Island Zone]] Act 1 in this matter is particularly problematic, normally causing the game to freeze. This is because hitting a checkpoint in a Zone without water will cause the checkpoint water level to be set to 00. This will result in water filling the entirety of Angel Island Act 1 when entered, a scenario which crashes the game.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Level state not cleared after a soft reset====
{{bug
| image=Sonic3 MD Bug AIZTitleCardinCNZ.png
| desc=This bug is similar in behaviour to the above. Start from the first Act of any Zone except Angel Island Zone or IceCap Zone, then do a soft reset. Return to the level select screen and select "[[Special Stage (Sonic the Hedgehog 3 & Knuckles)|Special Stage]] 2". End the Special Stage (either by success or failure), and the game will load Act 1 of the last Zone played, but will display Angel Island's title card.

At first, the Act will play normally aside from some Badniks loading the wrong art until the player reaches the end of the Act and defeats the mini-boss - Angel Island music will begin playing, and the second Act will not properly load, either getting the player stuck or leading them to the loopback of Act 1, and as such Edit Mode is required to fully explore. Other effects of this bug vary by Zone, such as [[Carnival Night Zone]] not resetting its background after the [[Bowling Spin]].
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Doilus Stage title cards====
{{bug
| image=Sonic3 MD DoilusStage TitleCard.png
| desc=The Gumball Machine [[Bonus Stage]] can be visited by selecting the sixth "2P VS" option the level select. However, exiting the stage does not take Sonic and Tails back to a regular Zone - the Bonus Stage simply loads again. Doing so corrupts the title card as the wrong artwork is loaded for its lettering (information comes from the Angel Island Zone load sequence), resulting in the pair visiting "DOILUS STAGE" instead of "BONUS STAGE".
| fixed=''[[Sonic 3 & Knuckles]]'' (for the Slot and Glowing Spheres bonus stages; the Gumball Bonus Stage is removed from the level select)
}}

====Strange palette for Knuckles underwater====
{{bug
| image=Sonic3 MD Bug KnuxUnderwater.png
| desc=By using the level select, it is possible to see Knuckles with strange palettes underwater in various places.
}}

====Flying Battery Zone's music loses synchronisation====
{{bug
| image=no
| desc=In ''[[Sonic the Hedgehog 3]]'', the music for [[Flying Battery Zone]] is present in the sound test, since the Zone was originally intended to exist in this game between Carnival Night Zone and IceCap Zone. In this version, the echo track of both acts' music will go off sync after the first loop, and slowly gain more and more delay behind the lead melody.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Data Select volume bug====
{{bug
| image=no
| desc=If one leaves the game running on the Data Select screen for about 47 minutes, a piece of percussion will increase in volume. A high quality recording can be found [http://www.youtube.com/watch?v=JmWgcM0CkKw here]
| fixed=''[[Sonic 3 & Knuckles]]''
}}

==Level-specific bugs==
===[[Angel Island Zone]]===
====Sonic's plane tail emblem====
{{bug
| image=Sonic3 MD AIZ PlaneEmblem 1.png
| caption=Before
| image2=Sonic3 MD AIZ PlaneEmblem 2.png
| caption2=After
| desc=As Sonic's plane shares the same palette line with Sonic, his initial transformation into Super Sonic causes the emblem on the tail to change from blue to yellow. Only three pixels are affected so it's easy to miss, but it does mean there's a visible palette error mere seconds into the game.
}}

====Return to Act 1====
{{bug
| image=
| desc=When Angel Island Zone catches fire, much of the internal mechanics of ''Sonic 3'' classes this as having started Act 2. When the (beatable) boss is encountered, the camera locks in place and like in most Sonic games, the preceeding level is shut off to the player.

But when the "real" Act 2 begins, all bets are off about whether this artificial barrier will be respected. Entering a Special or Bonus Stage and then returning in Act 2 removes the barrier, allowing players to backtrack not only to the start of what the player thinks is Act 2, but to the mid-point of Act 1 (classed as the start of Act 2 by the game). This is the only time in the series where walking back to a previous level is made possible, even if it is an oversight.
}}

====Get Tails stuck after last tunnel====
{{bug
| image=Sonic3 MD AIZ TailsRoll.png
| desc=If Tails enters the very last tunnel of Act 2 before Sonic, he will appear floating above the exit hole in his spinning animation on the other side. The second player won't be able to free him from this state - he'll be teleported and dragged along the floor of the Flying Battery sequence and only regain control when the boss appears.
}}

====Getting back to the regular stage after the last tube====
{{bug
| image=Sonic3 MD AIZ Act2EndPlatform.png
| caption=Sonic's not coming down - he's standing on an invisible platform off-screen.
| image2=Sonic3 MD AIZ Act2EndPlatform2.png
| caption2=Let's go left instead.
| desc=Prior to the chase sequence at the end of Act 2, Sonic and Tails are forced through a one-way tube. The Y position of the camera locks in place, and the game expects you to move to the right. However, a strange oversight means a solid platform exists off-screen, which can be reached if Sonic or Tails is travelling fast enough through the aforementioned tube.

Using this platform (and others like it), it is possible to navigate back to the left of the screen and back into the main level. Some graphics and objects are corrupted and only a small part of the stage is accessible, as the screen is still locked in place.

*[http://www.youtube.com/watch?v=ag78tNsR1vs Video]
}}

====Tails does not dodge bombs and then falls behind====
{{bug
| image=Sonic3 MD AIZ Act2TailsBomb.png
| desc=At the end of [[Angel Island Zone]] Act 2, playing as Sonic and Tails, you are chased by Eggman's "Flying Fortress", which drops bombs that are easily avoided simply by running at full speed. AI-controlled Tails doesn't understand this concept however, and will usually spend its time at the far left of the screen, being hit by bombs and being being dragged along by the camera.

In ''Sonic 3 & Knuckles'', Tails' AI behaviour was changed. While he will still be repeatedly hit by bombs, he will make more of an effort to catch up with Sonic, stopping just short of the safe zone.
| partialfixed=''[[Sonic 3 & Knuckles]]'' (behaviour altered) 
}}

====Avoid Hydrocity Zone====
{{bug
| image=Sonic3 MD AIZ AvoidKnuckles.png
| desc=At the end of Act 2, Knuckles jumps on a switch which breaks a bridge, forcing Sonic and Tails to drop down to Hydrocity Zone. However, if the player holds {{left}} and jumps at the correct time, they can make it back to solid ground. Control is never taken away from second-player Tails, so he can always get away if desired.

There's nothing to see and an invisible wall prevents Tails from getting to Knuckles (although with clever positioning of the capsule and a Lightning Shield, Sonic can get over there), so the only way to continue is to willingly make the drop.
}}

===[[Hydrocity Zone]]===
====Palette swap====
{{bug
| image=Sonic3PalleteGlitch.png
| image2=Sonic3 MD Bug HCZ NoWaterSpout.png
| desc=When the player goes through the underwater tube right at the start, the game will change the palettes accordingly. If the player proceeds to get back to the very first area where the fall down (easiest with Tails), all of the underwater tiles are now a very bright orange as the palette swap techniques no longer apply. If the player goes through the tube again, there'll be no water spout coming out of the wall.
}}

====Transparent tube is not transparent====
{{bug
| image=Sonic3 MD HCZTube.png
| desc=When Sonic and Tails are pushed up to the surface, they travel "through" some vertical tubing. The art suggests these are meant to be semi-transparent - you can see the background, but never Sonic and Tails.  
}}

====Non-animated scenery====
{{bug
| image=Sonic3 MD HCZ1NoAnimations.png
| desc=Just before the Act 1 boss, these cased black balls, which usually move from side to side, will stop animating.
}}

====Incorrect mid-boss music====
{{bug
| image=Hzsubboss.png
| desc=Hydrocity's mid-boss, the [[Big Shaker]], plays the music normally associated with Act 2 bosses. This could be considered a design choice, but is likely an oversight, given that the normal mid-boss track is reinstated in the ''[[Sonic the Hedgehog 3 Limited Edition]]'' prototypes and ''Sonic 3 & Knuckles''.
| fixed=''[[Sonic the Hedgehog 3 & Knuckles]]''
}}

====Tails wall collision====
{{bug
| image=Sonic3 MD HCZ2TailsWall.png
| desc=At the beginning of Act 2, Sonic and Tails are chased by a moving wall. When the wall has reached the end of its path, it is solid for Sonic, but as long as Sonic isn't standing right next to it, the wall has no effect on second-player Tails.
| fixed=''[[Sonic the Hedgehog 3 & Knuckles]]''
}}

====Make the wall go away====
{{bug
| image=Sonic3 MD HCZ2MissingWall 1.png
| image2=Sonic3 MD HCZ2MissingWall 2.png
| desc=To attempt to stop back-tracking, the green blocks/doors positioned straight after the moving wall in Act 2 are "replaced" by solid brown ones as the characters roll through. However, like all doors in the game, they will not shut if a character is standing below them.

If Tails is blocking the door and Sonic moves to the right (enough so that the moving wall is off-screen), moving back to the left will show that the wall has disappeared, allowing Sonic and Tails to return to the initial area. With help from Tails, Sonic can travel to the beginning of the Act, to reveal a big gap where the wall object used to be.
| fixed=
}}

====Clip through blue ramps====
{{bug
| image=Sonic3 MD Bug HCZ SpinDashUnderRamp.png
| image2=Sonic3 MD Bug HCZTailsFloorClip.png
| desc=The blue ramps only have solidity upwards, which means that if the player jumps towards them or has Tails fly/swim towards them they can pass through them as long as their Y-velocity is directed upwards. If you do get behind one, they can then walk into the base where it meets the floor and they will sink in. Doing a couple of Spin Dashes at that spot will lodge the player in the floor and can zip left and right. If they're coming from above, their solidity blocks are only 16 pixels large at any given spot (relatively small), so if they can get a Y-velocity higher than that then they'll have a chance of clipping through too. [http://twitch.tv/primat91/c/1506437 Video]

This bug also leads to an oddity in the section where the player goes through the second loop that leads to a vertical corkscrew that darts underwater, and is followed by a small tunnel and then a thick blue floor that curves up and then back down. With a well-timed jump or by swimming with Tails at a 45-degree angle as soon as they exit the tunnel, the player can go through the blue ramp in this area. Under the floor is nothing but the eventual bottom of the level. Incidentally spikes were placed under other supposedly inaccessible places of the Act, just not here.
}}

====Act 2's boss can be skipped, but will softlock the game====
{{bug
| image=Sonic3 MD Bug HCZ2Boss.png
| desc=After being swept through the tunnel into the cavern to face the [[Screw Mobile]] in [[Hydrocity Zone]] Act 2, it is possible to skip the boss battle by quickly running through the area to the right, where the animal capsule can be found and activated. The end of level music will play, and the points will be added up. However, the bomb drop and blast sounds can still be heard from the boss, and the water spout will not appear to take Sonic and Tails (or Sonic and Tails playing solo) to [[Marble Garden Zone]]. Also, the character name in the score tally will sometimes glitch. But all is not lost: if the console is reset and the player re-enters the save-select screen, their saved game will have been updated to [[Marble Garden Zone]] and will allow them to progress as normal.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Act 2 boss causes Super Sonic to revert to normal Sonic's sprites====
{{bug
| image=YellowSonic.png
| desc=While fighting the Screw Mobile, if you allow Super Sonic to be drawn to the water plume, Super Sonic will lose the custom sprites and will appear as regular Sonic (spikes pointing down instead of up) though the yellow color is retained.  His rings will also no longer count down.  Furthermore, once this has happened, defeating the boss will result in Sonic retaining the Super Sonic yellow color even after bursting the egg capsule open. The score tally will also appear with Sonic's name in yellow instead of blue. [http://www.youtube.com/watch?v=k8cKcuNlVjU Here] is the glitch in action.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

===[[Marble Garden Zone]]===
====Mid-boss can be defeated early, causing a crash====
{{bug
| image=Sonic3 MD Bug TunnelbotCrash1.png
| caption=Take control of Tails and defeat Tunnelbot.
| image2=Sonic3 MD Bug TunnelbotCrash2.png
| caption2=When the signpost lands...
| image3=Sonic3 MD Bug TunnelbotCrash3.png
| caption3=...the game will crash.
| desc=It is possible to defeat the [[Tunnelbot]] mid-boss by having a second player control Tails before it has been activated properly. By stopping Sonic before the screen has been locked for the mid-boss fight, and killing the mid-boss using Tails, the Act 2 loading sequence will be out of position and crash the game once the end-of-Act [[signpost]] has landed.
| fixed=''[[Sonic 3 & Knuckles]]''. The game forces the camera to pan to the right if Tunnelbot is defeated offscreen
}}

====Tails sometimes does not appear to fight Act 2's boss====
{{bug
| desc=Sometimes, [[Miles "Tails" Prower|Tails]] won't turn up for the [[Marble Garden Zone]] boss, when playing as either [[Sonic the Hedgehog|Sonic]] & Tails or Sonic alone. This is currently believed to happen at random.

Accessing this boss as Knuckles (only accessed by using cheats or glitches) in ''[[Sonic 3 & Knuckles]]'' will randomly cause the same issue. Another effect that may be related is sometimes you cannot move Tails up and down; that is most likely due to Tails spawning too early, so when EggRobo digs into the ground, stay on the ground and wait for Tails.
}}

===[[Carnival Night Zone]]===
====Super transformation barrel clip====
{{bug
| image=Sonic3 MD Bug TransformClip1.png
| caption=Transform while this barrel is moving to clip through it.
| image2=Sonic3 MD Bug TransformClip2.png
| caption2=Doing so allows Sonic to access Knuckles' route.
| desc=It is possible for the player to clip through barrels that can be manipulated by getting them moving, then transform as the barrel moves wildly. By doing this with the first barrel of [[Carnival Night Zone]] Act 1, the player can access Knuckles' route, but they will not be able to proceed past the breakable wall without debug mode.
}}

====Balloon palette====
{{bug
| image=Sonic3 MD Bug CNZSuperBalloon1.png
| caption=The balloon as normal.
| image2=Sonic3 MD Bug CNZSuperBalloon2.png
| caption2=When Super Sonic is active.
| desc=Some of the balloons use Sonic's palette line, meaning should he transform into Super Sonic, the balloons start flashing white and yellow.
}}

====Mid-air actions in anti-gravity====
{{bug
| image=Sonic3 MD Bug CNZ AntigravityMidAirAction.png
| desc=If the player starts hovering on the anti-gravity platforms while in a jumping state, they will be able to perform any mid-air actions (like the Insta-Shield) while hovering above the platforms. They cannot do this if they walk onto the platforms.
| fixed=''[[Sonic 3 & Knuckles]]''. Oddly, ''[[Sonic Jam]]'' reverts this bug in ''Sonic 3 & Knuckles'' as described [[Sonic Jam/Bugs#CNZ mid-air actions in anti-gravity|here]]
}}

====Wheel physics====
{{bug
| image=
| desc=In Carnival Night Zone, if a character lands on one of the three Super Ring Item Boxes under the the first wheel in the stage without breaking them (easiest to do with Tails due to his flying ability), the standard wheel physics will continue to apply even if they're on normal ground. What this means is that the gravity is set to a high and fixed value (i.e. no acceleration) and also that the gravity is to be applied downwards from the player character's current perspective, no matter which direction that might be; for example, if the player would run up a halfpipe, they'd start falling to the side feet first. This bug can be stopped by jumping.

*[http://twitch.tv/primat91/c/1506487 Video showing the bug in action]
}}

====Stand on top of cannons====
{{bug
| image=Sonic3 MD CNZCannonStand 1.png
| image2=Sonic3 MD CNZCannonStand 2.png
| desc=It is possible for Tails to lift Sonic on top of the cannons. Sonic will stand on top, while Tails will go inside.

If Sonic starts Spin Dashing in this state, he will slowly decend into the ground. If Tails subsequently fires, Sonic will enter a pseudo-rolling state, where he won't be able to jump, have the Spin Dash trail behind him at all times, and have all sorts of collision problems. It can be fixed with interacting with an object such as the giant meshes or an enemy.
| partialfixed=''[[Sonic & Knuckles Collection]]'' (behaviour altered) 
}}

====Tails' strange appearances in Act 2====
{{bug
| image=Sonic3 MD Bug CNZTailsSuddenDeath.png
| desc=If Sonic, playing alone, reaches the end of [[Carnival Night Zone]] Act 1 without dying or entering a Special or Bonus Stage since the start of the Zone, Tails will be heard and then seen suddenly dying after the mini-boss is defeated. After the sign falls and Act 2 begins, Tails will reappear and fall into the stage, but will be unable to move, and must be left behind. Should Sonic manage to also then reach the end of Act 2 under the same conditions, Tails will be seen dying again after defeating [[Eggman]], and will spawn again on the screen after the "Act 2 completed" messages complete. When moving to enter the cannon, Tails will be crushed against the ledge as the screen is forced to the right.

This occurs because Tails is not unloaded after being spawned for the start of the Zone in which he delivers Sonic from the end of the previous Zone ([[Marble Garden]]).  Restarting from a Star Post or giant ring will recreate the level objects, and Tails is not respawned.

| fixed=''[[Sonic 3 & Knuckles]]'' (Tails despawns as soon as he leaves the visible screen area)
}}

====Ceiling trap====
{{bug
| image=Sonic3 MD Bug CNZCeilingTrap1.png
| caption=Run up the floor-to-ceiling transfer here...
| image2=Sonic3 MD Bug CNZCeilingTrap2.png
| caption2=Another one of "Dr. Robotnik's diabolical traps".{{fileref|Sonic3 MD US manual.pdf|page=29}}
| desc=A ceiling corner in Act 2 has faulty collision. Should Super Sonic jump into the wall-to-ceiling transfer and run along the ceiling, he will be stuck in the ceiling, unable to escape.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Carnival Night boss can drop its weapon out of the arena====
{{bug
| desc=It is possible for [[Graviton Mobile]] to drop the "ball" into the shaft that was used to get up to the boss fight. The shaft is just to the left of the boss fight area, and the ball is able to reach it since is not affected by the screen lock.  The top of the shaft is blocked by an object to prevent the player falling back through, but the ball is not programmed to interact with this object. [http://www.youtube.com/watch?v=-7vJJLA6LFQ This video] uses debug to show what happens.
}}

====Incorrect running up sprites====
{{bug
| image=Sonic3 MD Bug CNZ OldMeshSprites.png
| desc=When running up the long mesh tubes that the player can hang on to, Sonic will show his sprites from the Nov. 3, 1993 prototype, until he starts going down, which corrects to his final, sideways hanging sprites.
}}

===[[IceCap Zone]]===
====Tails and ice cages====
{{bug
| image=Sonic3 MD Ice 1.png
| image2=Sonic3 MD Ice 2.png
| image3=Sonic3 MD Ice 3.png
| desc=Littered through IceCap Zone are breakable ice "cages" which surround many monitors and springs. Unlike most breakable objects, Tails can break them when acting as Sonic's partner, causing odd results should Sonic be standing on top of one. Breaking the cage with Tails causes Sonic to react as if he had broken it, while Tails will find his vertical coordinate locked, balancing in mid-air. Tails can move left and right across the X axis without being affected by gravity, with normal gameplay only being restored if Tails interacts with an object (or is too far off-screen and is subsequently respawned). Jumping will cause gravity to take affect, but collision issues remain wonky and can allow Tails to pass through walls.
| partialfixed=''[[Sonic 3 & Knuckles]]'' - the roles are reversed, with Sonic becoming "stuck" instead
}}

====Super Sonic can be hurt by icicles====
{{bug
| image=Sonic3 MD Bug ICZIciclePain.png
| desc=In Act 1, by using the vertical wrap glitch, Super Sonic can gain access to Knuckles' area. While in this area, there are icicle spikes that harm Super Sonic, thus the player loses all of their rings and Super Sonic transforms back into Sonic.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Tails dies when descending the first slide====
{{bug
| image=Sonic3 MD Bug ICZTailsDeath.png
| desc=In Act 1, Tails will lose a life when going down the first slide past the first Star Post in the initial run of the Act. This can be avoided if you can manage to re-enter the Act, such as returning from a Bonus Stage or Special Stage (a giant ring can be found just above said slide), or after losing a life and respawning from the checkpoint. After returning in one of these manners, Tails can go down the slide without issue; however, dying and returning to the beginning of the Act, and not from the checkpoint, will not fix the issue.

The bug is caused by an oversight in the code. The vertical looping flag on the initial run is set during Sonic's snowboard sequence at the beginning of the Act. Since this sequence is not triggered for Tails, the flag is not set when entering the Zone for the first time. When Tails goes down the slide, which happens to be at the bottom of the level, the lack of the looping flag treats this as Tails falling into a bottomless pit.

Amusingly, the English manual makes an oblique reference to this bug, while trying to avoid identifying it as such: "In the IceCap Zone and throughout the game, avoid having Tails get stuck in passageways or get caught in traps. Have Tails activate Starposts or enter into a Special Stage as quickly as possible."{{fileref|Sonic3 MD US manual.pdf|page=29}}
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Act 1 background glitch====
{{bug
| image=Sonic3 MD IceCapAct1Tunnel.png
| desc=Towards the end of the level, Sonic and Tails go outside and new background art is loaded. The game usually masks the loading while the duo are in a tunnel leading outside, but if the user is travelling fast enough (for example, with Super Sonic), you can get through (and sometimes be physically stopped) before the art has been decompressed, leading to a temporarily corrupt background. The problem is exacerbated in ''Sonic the Hedgehog 3 & Knuckles'' if [[Hyper Sonic]] is involved.  
}}

====Sonic won't stop running====
{{bug
| image=
| desc=In the beginning of Act 1, use debug mode to go to the highest position, then hold the {{right}} button until you get into the boss arena, then disable the debug mode. Sonic won't stop running super fast, and if Tails is following Sonic, Tails will respawn out of nowhere after beating Act 1.
| fixed=
}}

===[[Launch Base Zone]]===
====Failing to rotate on rotating drums====
{{bug
| image=LBZSpinningBug.png
| desc=If the player's character comes to a natural stop on the spinning drums after being rolled up into a ball, he will be using his standing sprite instead of the rotating sprites.
}}

====Bubble bouncing on rotating drums====
{{bug
| image=Sonic3 MD LBZDrumBubble.png
| desc=Using the Water Shield to bounce on a giant rotating drum causes the wrong animation to show. Instead of the bounce animation, it uses the first frame of the rotating animation.
}}

====Triggering the booster infinite times====
{{bug
| image=LBZBoosterBug.png
| desc=If the player does a [[Spin Dash]] in the right place and at the right time, the character will trigger the booster for an infinite number of times, as long as he maintains his charge of the Spin Dash.
*[http://www.youtube.com/watch?v=zdtlWEc-b4w Video]
}}

====Corrupt Corkey graphics====
{{bug
| image=Sonic3 MD LBZ Corkeys.png
| desc=An oversight with this Star Post in Act 1 means that should the player die, the [[Corkey]] Badniks to the right will initially load in using title card graphics. Once the title card has left the screen, the normal Corkey graphics will load in.

While technically this glitch could happen anywhere in the game, ''Sonic 3'' usually has its Star Posts positioned further away apart from Badniks to ensure this doesn't happen.
}}

====Super Sonic can glitch through elevators====
{{bug
| desc=When playing as Super Sonic in [[Launch Base Zone]] Act 1, if the player holds left whilst Super Sonic is inside a "spinning elevator", he will glitch outside the elevator in the "push" pose before the doors of the elevator open.
}}

====Objects are left behind when Knuckles blows up the building====
{{bug
| image=Sonic3 MD LBZAct1BuildingFly.png
| desc=Before the boss of Act 1, Knuckles blows up a building and Sonic and Tails are forced to jump out of the nearest opening. When the pair land, however, the camera's Y position is not locked into place - with Tails you can fly up and see the objects Knuckles couldn't destroy.
}}

====Beat Eggman in Act 1====
{{bug
| image=Sonic3 MD LBZAct1Eggman 1.png
| image2=Sonic3 MD LBZAct1Eggman 2.png
| image3=Sonic3 MD LBZAct1Eggman 3.png
| desc=Before confronting Knuckles again and fighting the [[Twin Hammer]] boss, Eggman is briefly seen carrying a package as Sonic and Tails make their way up a tower. Usually Eggman flees the scene as soon as Sonic reaches the platform below, but he's not scared of Tails, who, if controlled by the second player, can freely attack Eggman at his leisure. See [http://www.youtube.com/watch?v=fo8G_-ti170 this video].

Eggman takes 256 hits, but can be defeated, causing him to "pop" like a Badnik, award 100 points and spawn a trapped animal. Defeating him here causes problems later on, however - the tower Knuckles bombs won't fall down, and the player will be forced to wait for a time over.
}}

====Super Sonic can clip through the wall====
{{bug
| image=Sonic3 MD Bug LBZ2Clip.png
| desc=Similar to Carnival Night Zone, the player can use Super Sonic to clip through a wall at the first section where the player can enter a water pipe, taking an unintended shortcut.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

====Avoid fighting [[Ball Shooter]]====
{{bug
| image=Sonic3 MD BallShooter 1.png
| image2=Sonic3 MD BallShooter 2.png
| desc=The first of three bosses for Act 2, [[Ball Shooter]] can be avoided if the player can get behind it before Eggman enters. Rather than dodging balls and timing jumps, the player just needs to attack the "stand" until it explodes.
}}

====Super Sonic can be hurt by the final boss====
{{bug
| image=Sonic3 MD Bug BigArmHurtsSuperSonic.png
| desc=In Launch Base Zone Act 2, when the final boss ([[Launch_Base_Zone_bosses#Third_Boss_.28Big_Arm.29|Big Arm]]) slams Super Sonic against the ground, he can still lose rings.
| fixed=''[[Sonic 3 & Knuckles]]'' (Sonic and Tails don't fight Big Arm, [[Super Knuckles|Super]]/[[Hyper Knuckles]] will simply bounce off while making a spring sound)
}}

====Water in the ending====
{{bug
| image=Sonic3 MD Bug EndingUnderwater.png
| desc=If the player defeats the remaining two bosses quickly enough, which requires Super Sonic in order to do so, the player can stop the [[Death Egg]] quickly enough for the platform to sink back into the water during the ending, leading to Sonic/Super Sonic's ending sprite having a bizarre underwater palette.
| fixed=''[[Sonic 3 & Knuckles]]''
}}

===Competition Mode===
====Ring glitches====
{{bug
| image=Sonic3 MD Bug Competition Ring1.png
| image2=Sonic3 MD Bug Competition Ring2.png
| caption=Tails "loses" his "Ring"...
| caption2=...and now Sonic suddenly has one.
| desc=A [[Ring]] can be collected as an item in Competition Mode which will protect the player from the bomb item. However, the Ring will not display the correct graphics when dropped, instead using graphics from the goal post. It gets even worse when the second player is involved, as the dropped Ring will be added to the first player's item slot if picked up by the second player. Additionally, if the second player has the Ring and loses it, it won't disappear from their item slot and can be picked up by either player, essentially duplicating the Ring.

The reason this happens is due to the dropped Ring object being the same one from the main game and does not adequately account for the second player. Additionally, the game attempts to remove the second player's Ring from the first player's item slot when it's not supposed to, and the dropped Ring art is loaded to a different VRAM address{{ref|https://s3unlocked.blogspot.com/2017/09/rings-are-fundamentally-broken-in-2p.html}}.
}}

====Balloon Park cheat====
{{bug
| image=Sonic3 MD Bug BalloonParkCheat1.png
| caption=Bounce off this yellow balloon...
| image2=Sonic3 MD Bug BalloonParkCheat2.png
| caption2=...then run up the wall and ceiling.
| image3=Sonic3 MD Bug BalloonParkCheat3.png
| caption3=You will clip through the loop.
| desc=[[Balloon Park Zone]] has a collision glitch that can be exploited to beat the Zone in under 10 seconds. Right at the beginning, jump down to the left where the yellow balloon is (if you accidentally touch it, wait until it reappears). Jump on the top of the balloon and walk up the wall next to it. After reaching the top of the level (which is a quarter-loop) you will make a move like you are walking around a normal loop and move upwards. You will get stuck there and there is no way to escape either. However, now you can move to the right and do the whole course in a very low time. You only need to do 1 jump per lap to jump over a small gap.
| fixed=''[[Sonic 3 & Knuckles]]''. However, due to ''S3&K'' using FRAM data from the ''Sonic 3'' cartridge, records achieved using the cheat will display in ''S3&K''
}}

==Unsorted==
===IceCap===
*[[Sonic]] and/or [[Tails]] can walk over the top of the screen in Act 2.

==References==
<references/>

{{S3Omni}}