A chase sequence is an event where Samus is chased by a lethal hazard, often dealing significant damage or outright instantly killing her if caught. They are similar to countdowns, albeit untimed. Super Metroid, Metroid Fusion, Metroid: Zero Mission, Metroid: Samus Returns, and Metroid Dread all have a form of chase sequences. In later games after Super, Samus is chased by significant antagonists, who are defeated in later battles once she has acquired the necessary power-ups. In some cases, chase sequences overlap with countdowns.
Chase sequences in the series[]
Super Metroid[]
Right after acquiring the Speed Booster, the lava in the room and the hallway before it begins to rapidly rise, and Samus must use her newly acquired power-up to outrun the rising lava. Rising scalding-hot lava also occurs in some rooms in Ridley's Lair.
After entering Tourian and defeating all the Metroid larvae, Samus encounters several creatures drained of their energy, crumbling into dust at the slightest touch. She then encounters a live Sidehopper which is shortly attacked by the Big Metroid, draining it into a husk, before chasing after Samus. The anomaly is invulnerable to her weapons, and once it latches on it will weigh her down; however it stops at 1 energy, revealed to be the Baby as it recognizes Samus as her mother, and flees in shame. It is possible to escape into the next room before the Metroid latches on, although this is extremely difficult due to its high speed.
During the countdown to Zebes' destruction late in the game, scalding-hot lava rises up in certain areas of Crateria (most notably in the Torizo room where the Etecoons and Dachora were located at after saving them), requiring Samus to keep moving to her ship.
Metroid Fusion[]

Samus fleeing the SA-X in her second TRO encounter with the being.
Over the course of the game, Samus is relentlessly pursued by the SA-X, an X Parasite mimicking her at full capacity, and deals massive damage to her with its Ice Beam and Super Missile. Until the end of the game, Samus has no way to combat it, forcing her to hide and flee from its pursuit. Once Samus acquires Ice Missiles, she can freeze it briefly.
The SA-X appears in the following locations:
- Sector 2 (TRO) (First encounter): After defeating Zazabi, Samus falls into a shaft. The SA-X calmly walks beneath her to simply open a hatch and leave. If disturbed, the SA-X will hunt Samus until she retreats to the upper section, where it will run to the end of the hall and resume its normal routine.
- Sector 6 (NOC): Samus reaches a series of Power Bomb Blocks, her only way forward is a small Bomb Block tunnel. Once inside, the SA-X enters the room and walks toward the end to lay a Power Bomb, opening up the path. It will then proceed forward, jump down, open a hatch and leave. If it catches her, then loses sight, it will constantly run back and forth until Samus escapes into the next room.
- Sector 5 (ARC): Shortly after Samus acquires Power Bombs, she enters a newly unexplored room. Almost immediately after, the SA-X enters behind her. Ahead of Samus is a pillar that she can jump over and hide behind; the SA-X will walk up to the pillar before turning around to leave. Further ahead are Power Bomb Blocks, but this is actually a trick to reveal a dead end tunnel, an upper alcove of Bomb Blocks, and the pillar behind her also being Bomb Blocks and thus alerting the SA-X. Should Samus climb into the upper alcove, the SA-X will repeatedly fire its Ice Beam through the wall until Samus escapes the room.
- Sector 2 (Second encounter): After Samus activated the Auxiliary Power Station, the SA-X laid in wait for her upon her return to Sector 2, forcing a direct encounter and giving her chase through several vines and shutters until she reached a room with a pillar to hide behind. Having lost sight, the SA-X would turn around and give up the chase.
Eventually, one of ten SA-X is defeated in a battle in the Operations Deck, and absorbed by Samus later in the Docking Bays. All other SA-X are destroyed along with the Biologic Space Laboratories research station and Restricted Laboratory.
Metroid: Zero Mission[]

Samus hiding from a Zebesian.
After escaping from Tourian and crash landing near the Space Pirate Mother Ship and Chozodia, Samus loses her Power Suit and is left in her Zero Suit, with only her Paralyzer as a means of defense against her pursuers. With the area under heavy security by Zebesians which deal significant damage to the Zero Suit, Samus is forced to move stealthily, or flee and hide until the alarms deactivate. Only after completing the Ruins Test and gaining the Fully Powered Suit can Samus cease fleeing and fight back.
Metroid: Samus Returns[]

Samus runs from the Diggernaut's drill arm
In Area 4, Samus finds a broken Chozo Statue without its Item Sphere. Shortly afterwards, she encounters the Diggernaut and attacks it, but it is invulnerable to her current weapons. Aggravated, the Diggernaut prepares to sweep its drill arm. Samus is forced to outrun the drill through several long hallways, which instantly kills her on contact. She eventually reaches a narrow Morph Ball tunnel and hides in it to avoid being crushed; the Diggernaut is unable to scan her presence and assumes she is dead, then spits out the Item Sphere containing the Space Jump and leaves. Later on in her mission, Samus destroys the Diggernaut.
Metroid Dread[]

Hiding from E.M.M.I.-02SM, which is in Patrol Mode.
Over the course of the game, Samus meets seven E.M.M.I., virtually indestructible robots programmed to pursue her. They are scattered across ZDR's E.M.M.I. Zones. Due to their virtually indestructible nature, Samus has no choice but to move cautiously in their zones and flee from their pursuit. Should they catch her, they will grab and then impale her in the sternum with a needle-like apparatus, instantly killing her unless she performs a well-timed Melee Counter. Only after destroying a Central Unit and acquiring the Omega Cannon can Samus fight back against the E.M.M.I.
Shortly after acquiring the Morph Ball and using a Red Teleportal to move from Cataris to Artaria, Samus enters a room to activate a thermal power flow machine. However, the room suddenly destabilizes with fire spewing out of the pipes and extreme heat begins to build up. Samus must escape from the room, with fire, debris and shifting mechanisms obstructing her path, before the extreme heat catches up and kills her.