A roll shot or roll shooting is a technique possible in both Metroid Prime and Metroid Prime 2: Echoes. It involves shooting a Beam or Missile in the process of unmorphing. This trick can save minor amounts of time throughout a run, usually when rolling into portals or towards a door. In order to perform a roll shot, the following requirements must be met:
- Be morphed.
- When unmorphing, press A and X on the same frame (or Y and X if opting for a Missile).
- In Prime 1, the Arm Cannon is pointing towards the ground when rollshotting. This limits you to only being able to shoot things directly underneath you.
- In Echoes, Samus must be on the ground (or jumpstate 0); it is impossible to do this airborne, even in jumpstate 4.
- This can cause issues in areas that don't have flat ground, as Samus may find herself in jumpstate 4 on the frame you attempt the roll shot, making it not work even if you do the inputs correctly.
A side effect of performing a roll shot is that Samus will begin charging whatever Beam is equipped after the roll shot, or if Samus has Seeker Missiles, will begin to initiate them after a Missile. This can sometimes be useful with Power Beam if you want to start charging a Super Missile early, or if you want to fire Seeker Missiles quickly as well.
To avoid laying a Power Bomb when attempting to roll shot with a Missile, lay some Morph Ball Bombs just before the roll shot, so the Bomb counter cooldown prevents the use of a Power Bomb. Also, if attempting a roll shot onto a door, be sure not to get too close to the door, as your shots will go through the door and miss it entirely.
The video below shows an example of a roll shot on the right side.
Roll Shot Out of Screw Attack
It is possible to perform a roll shot out of a Screw Attack, because the Screw Attack is technically part of the Morph Ball. This is also frame perfect, and involves pressing A or Y on the same frame that the camera starts panning into Samus.
TODO: Video of roll shot out of SA