Sequence Breaking

A Sequence Break is an act that breaks the standard sequence of events in a game ("taking another way through the game than a player is likely to use on the first play-through"). This may amount to collecting an item earlier than intended or skipping a segment entirely. Sequence breaks usually rely on glitches, but sometimes creative thinking is enough. Efficient sequence breaking is the key to most time improvements in speed running. For example, in Metroid: Zero Mission, it is possible to kill Ridley before killing Kraid, and also obtain the Varia Suit before the Ice Beam.

With the possible exception of Metroid II: Return of Samus, sequence breaks are ubiquitous in the Metroid games. In fact, many sequence breaks seem to have been known to the developers. For instance, the secret Wall Jumping and Bomb Jumping techniques in Super Metroid directly lead to several sequence breaks, but these moves mostly lack practical use otherwise. Further, it is nearly impossible to get stuck or cause crashes in Super Metroid when entering areas without the supposedly required equipment, indicating that the designers were aware of the possibility that players would do so.

List of Sequence Breaks
''== NOTE == Most of these glitches have been fixed in Metroid Prime Trilogy for the Wii. Only the gamecube versions of MP1 & MP2 have all of the glitches present.''

Metroid Prime

 * Using the Scan Dash glitch allows for the Space Jump to be acquired before any other upgrades.
 * Early Plasma Beam via a series of difficult jumps.
 * Early Ice Beam via a clipping glitch.
 * Early Gravity Suit via part of the "Early Plasma Beam" (namely passing the Twin Fires Tunnel without the Spider Ball.)
 * Skipping the Hive Mecha via an L-Lock Spring Space Jump.

Metroid Prime 2: Echoes

 * Using carefully a excecuted bomb jump and screw attack, a player is able to completely bypass getting the keys to the Ing Hive Temple.

Metroid Prime 3: Corruption

 * It is possible to skip both Turrets by using a Spring bomb jump where the valley at the end of the second one is

Super Metroid

 * Early Ice Beam via Machball.
 * Early Wave Beam via the Wall Jump technique.
 * Late Speed Booster via doing other sequence breaks before getting it.
 * Early Grapple Beam via having other items before you're supposed to.
 * Early Missile Expansions and Energy Tanks via numerous ways.
 * Early X-Ray Scope via the Wall Jump technique.
 * Getting into the Wrecked Ship without Grapple Beam via jumping while dashing and wall-jumping technique.
 * Early Gravity Suit via getting into the Wrecked Ship early. See above.
 * Getting to Draygon without the Grapple Beam via getting the Gravity Suit early (see above) and the wall-jumping technique.
 * Early Super Missiles via Machball.
 * Late high jump boots by wall jumping/dashing.

Zero Mission

 * Early Varia Suit via an Infinite Bomb Jump or Ice Beam (ice beam method takes incredible patience).
 * Early Super Missiles via Morph Ball Shinesparks.
 * Early Screw Attack via Wall Jump, Infinite Bomb Jump, or Shinespark.

Metroid Fusion

 * Certain save rooms have breakable blocks about two or three blocks up from the ground. These aren't supposed to be accessible until the Spring Ball is acquired but if you get right next to the wall, jump as high as you can and than immediately go morph ball and move to the right you can get into it.