Super Metroid Map Rando
Version: 28
Open: Key items, tanks, and ammo are placed throughout the game in roughly a uniformly random way (subject to logic constraints to ensure the game is beatable), which generally allows multiple pathways for progression.
Semiclosed: Key items are placed sparingly until the final stage of item placement, tending to limit the player to a single intended progression sequence for much of the game. Energy Tanks are placed in roughly a uniformly random way, as are additional Super and Power Bomb packs after the first pack.
Closed: Key items, tanks, and ammo (other than Missiles) are placed sparingly until the final stage of item placement, tending to limit the player to a single intended progression sequence for much of the game.
Note: Even on the "Easy" difficulty, the seeds can be challenging, particularly in the early game. We are still working on improvements to better align the game's difficulty with the intended level.

The ability to crouch before jumping to reach higher ledges. Commonly paired with a Down Grab.
The ability to aim down to reduce Samus' hitbox to reach higher ledges. Commonly paired with a Crouch Jump.
Navigating heat rooms without immunity to heat damage.
Infinite Bomb Jump. Using consecutive bomb jumps to gain height indefinitely.
The ability to use the Speed Booster to store a charge, then fly in a direction until an obstacle is hit.
Navigating Maridia without Gravity. This is not required for simple underwater platforming where missing a jump does not leave the player stuck somewhere, or for falling down a submerged room.
Jump off walls, as taught by the Etecoons

Using SpaceJump to carry SpeedBooster's blue suit into some speed blocks that couldn't be reached just by running and jumping
The ability to break blocks above Samus while maintaining an ongoing IBJ.
A horizontal bomb jump using a single bomb. Since it uses one bomb, it works with PBs as well.
Basic variant of jumping into a two block high space and performing the actions needed to clip up through the ceiling. This often uses enemies, so is required for enemy clip enemies that are extensions of canUseEnemies.
The ability to reliably jump while landing on a crumble block. This may employ the small amount of jump buffering the game offers.
Performing a Crystal Flash.
Using a Crystal Flash to take advantage of the fact it forces Samus to stand up.
Taking damage from an enemy to assist Samus in her movement
The ability to open a left-facing blue or green gate from the right, using missiles or supers.
Turning off Gravity Suit right after the start of an underwater jump to achieve higher height
Using i-frames to setup a jump from a spike floor or wall
The ability to start an IBJ from a jump. Can be required in strats that need Samus to IBJ up faster or to avoid something near the ground.
Performing the same input as a mockball, but in midair, in order to maintain forward momentum while morphing in midair
Using a Mochtroid's movement to climb upwards by continually freezing it higher up
Using a frozen Mochtroid to clip through a one-tile-high wall.
Maintaining running speed while morphed, by holding jump and down (to crouch) during a lateral jump, then morphing as Samus hits the ground while holding jump and transition from holding down to holding forward. Sometimes referred to as a Machball.
Jumping off a ledge while moonwalking to fall with an uncapped speed
Piggybacking on top of a climbing snail to get up a wall
Using a lateral mid-air morph to bounce off a surface with SpringBall while retaining previous momentum.
Quickly press and release forward and then immediately press jump (after stopping) to spin jump with no horizontal movement. Can be done walking or running to slightly different effect.
Taking advantage of the smaller hitbox of spinjump and down-aim to squeeze through two-tile gaps.
Using an enemy in a room to accomplish something that couldn't be done if it weren't there
Can use Ice Beam to freeze enemies to use as platforms, or as walljump supports, to reach higher areas
Force Samus to stand up, from a crouching position, by canceling use of the XRay Scope while turning around

A mid-air morph that has to be done within an elevation difference of 3 tiles (with a ceiling removing any extra room). It's a lot more precise than with more room.
From a submerged platform, setting up a single bomb jump above the water line to propel Samus up and out of the water.
Repeatedly freezing a crab to climb up a wall, using no other support. This does not include the simple act of using a frozen crab as a stepping stone, even on a wall or in midair.
The ability to reliably spin jump while landing on a crumble block. This is much tighter than regular crumble jumps because the jump buffering does not help.
Using grapple to propel yourself upwards, then continuously morphing/unmorphing/jumping in midair to climb upwards
A horizontal bomb jump using two bombs. Longer range than single HBJ, much harder to execute, doesn't work with PBs.
The ability to pass through some enemies undamaged by shooting. May involve running through the enemy after making its hitbox inactive (e.g. Metal Pirates) or while the enemy has iframes (e.g. using Plasma).
Being able to glitch through the Mother Brain zebetites by using a frozen Rinka and iFrames.
Doing a gravity Jump in lava, causing Samus to take damage
Clipping into the Maridia tube from above by unmorphing.
Being proficient at avoiding Metroids
A walljump that needs to be performed at a fairly precise spot in order to yield the desired result.
The ability to get out of water by walljumping while the water is at its lowest point, and to do so in a timely manner, e.g. before a Yapping Maw drags you into a sand pit.
Setting up a Mochtroid climb from a sand floor, where failure in a suitless environment can mean death
Shooting a large number of off-screen shot blocks, overloading the memory and making it possible to clip through otherwise solid blocks. Made famous by its use in Frog Speedway.
Manipulating a snail's position to setup a ceiling clip.
Reaching a higher than normal height with a jump, by morphing in mid-air and then turning on SpringBall while still climbing upwards. This makes it possible to use SpringBall while Samus is still climbing upwards, for an additional jump.
While performing a stationary vertical jump, it's possible to mid-air morph in a manner similar to a lateral mid-air morph. Doing this immediately gives lateral momentum equivalent to maximum walk speed. This is meaningless under normal physics, but has underwater applications.
Navigating deep lava without Gravity. This isn't limited to the Lava Dive Room, but it does exclude all rooms with just shallow lava.
The ability to shoot a Super Missile at a precise location to hit an offscreen inanimate target, e.g. a Super block.
Executing a jump that requires very precise timing
Can use Ice Beam to freeze enemies in especially precise positionings.
Moving along a 2-tile-high passage while standing up by repeatedly spin-jumping and then pressing down. The tech comes with softlock risks without Morph Ball, but this is the safer variant where Morph is available and no softlock can occur.
Canceling an aim angle while crouching and turning around, to wiggle to the right
A tech that involves mid-air morphing to drop a Morph Bomb or PB, then mid-air unmorphing to briefly hover above the bomb, then using the bomb blast to go just a bit higher than max jump height
The ability to reach targets on the other side of a room by shooting Wave Beam at the right spot in the opposite wall.

Getting up a 2-tile-high jump in a morph passage by mid-air morphing off the opposite wall
Being proficient at avoiding the baby Metroid
Executing a strat that requires waiting or doing the same thing over and over again for over 3 minutes, even with good execution
Using a frozen Beetom to perform a ceiling clip
Continuous Walljump. Doing a precise forward jump that causes Samus to move back down right after the top of a wall while retaining her momentum. This leads to a tiny window where a walljump can be performed, still with the original momentum.
A tech that involves multiple damage boosts with precise timing. No room for missing one of them.
A precise walljump that additionally needs to done as far from the wall as possible.
Using the SpringBallJumpMidAir twice during a single jump to gain even more height. This only works underwater with HiJump. This consists of a tight variant of SpringBallJumpMidAir, then turning off spring ball, then a second SpringBallJumpMidAir all while still climbing upwards.
Using grapple jump off a Draygon turret
Climbing a wall with consecutive walljumps very quickly, e.g. for setting up a full halfie.
Positioning Samus at the very edge of a platform, facing away, then turning around and jumping to initiate the jump from a position that is off the platform (and slightly below it)
Executing a gravity jump off a walljump
For delayed walljumps that require extreme precision, in the vicinity of pixel+frame perfect.
Though using the same techs, the setup is a bit different for left-facing doors. It requires a dashing stationary spinjump into a doorcheck, then holding down as Samus arrives in the other room. Then use normal X-Ray climbing.
The ability to identify a bug enemy that moves in a diving pattern (Mellow, Mella, or Menu) and inches upwards or downwards with each dive. Once that enemy has been identified, subsequently making it dive repeatedly until it is at the proper height to execute a strat.
Moving along a 2-tile-high passage while standing up by repeatedly spin-jumping and then pressing down. Comes with softlock risks without Morph Ball.
Using a frozen Multiviola to clip through a one-tile-high wall.
A tech common to all ice clips except Mochtroid (which lines up perfectly so is pretty trivial). It requires either pixel perfect enemy positioning or the ability to force a standup with XRay.
Setting up an ice clip at exactly the right pixel, so the clip can work without the leniency allowed by an X-Ray standup
Using a frozen Puyo to clip through a one-tile-high wall.
The combination of a crumble quick drop, and landing on a lower surface and jumping back over the crumble block before it re-forms.
Being able to glitch through the second Zebetite barrier, clipping through it by morphing/unmorphing/remorphing on a frozen Rinka.
Enter the partner door (which faces left in the adjacent room) with a stationary spinjump moving away to touch the transition with momentum that will get you stuck in the destination door. That destination door is right-facing in the room where the X-Ray climb happens. Then use the X-Ray's forced standup trick to climb up through in-bound walls.
The ability to start an IBJ off a jump on sand. Pretty obnoxious.
Being able to glitch through the Mother Brain zebetites by using a shinespark and iFrames. The tech itself isn't that difficult, what makes it difficult with the vanilla layout is getting the short charge.
A springball jump that starts with a walljump to gain more height. It often relies on the momentum change when equipping or unequipping SpringBall while morphed and moving horizontally.
Using a series of rapid, consecutive wall jumps underwater, on two nearby walls, to climb upwards.
Jumping during a spike in the speed-to-jumpHeight chart (when Speed Booster is active) to achieve a higher jump height than if done with all the available running room
Using a frozen wall crawling enemy (such as a Zeela or Geemer) to perform a ceiling clip
Managing to break free of the water while doing a sunken dual wall climb, without the help of space jump
All-purpose tech for X-Ray climbing by repeatedly using X-Ray's forced standup trick to climb up through walls. This tech is uncoupled from different setups that place Samus in a position to do this and only refers to the actual climbing portion.
Note: ROM may take a while to generate. For fastest results, click "Generate ROM" only once and wait patiently. If it times out, try again with a different random seed. This is still in an alpha stage of development, so bugs are expected. If you encounter a problem, feedback is welcome on GitHub issues. Also feel free to stop by the Discord: let us know if you find a cool seed (or a broken seed), if you have questions or ideas for future development, or if you're streaming the game!
Things to know
  • Certain items do not spawn until the planet is awakened, by exiting Pit Room (old Mother Brain room) with Morph and Missiles collected.1
  • Certain items do not spawn until Phantoon has been defeated.
  • Phantoon's Room is always two rooms away from the Wrecked Ship Map Room, and both are in the same area as the Wrecked Ship Save Room.
  • Items are always marked by dots on the map. Map stations, refills, and major bosses (G4 and Mother Brain) are marked by special tiles.
  • Missile Refill stations refill all ammo types: Missiles, Supers, and Power Bombs.
  • Gravity and Varia behave like Progressive Suits in other randomizers, each giving 50% reduction in enemy damage (stacking to a combined 75%).
  • Mother Brain has been changed to take double damage from Supers.
  • The current tile can be marked un-explored on the map by pressing Angle Up and Item Cancel simultaneously. To be effective, these inputs must be held while exiting the tile, since otherwise the game will immediately re-explore the tile.
  • Saving at a different save station from the last save will advance to the next slot before saving, so you can return to an earlier save in case you get stuck.
  • Samus collects & equips all items (excluding beams, ammo, and tanks) when acquiring Hyper Beam.

Known issues
  • Even if the tech is not selected, wall jumps and crouch-jump/down-grabs may be required in some places.
  • Some sound effects are glitched (due to changing the music).
  • Door transitions generally have some minor graphical glitches.
  • The end credits are vanilla.
Change log
Note: Previous versions of the rando can be accessed by clicking the links below. These may take about 15 seconds to load.

Version 28 (2022-01-10):

  • Overhaul of the item placement algorithm:
    • The algorithm now runs faster, especially on Easy and Open modes, which should greatly reduce or eliminate timeouts that were common before.
    • Key items are now only placed at locations that are both able to be reached from the Ship and able to return back to the Ship without the use of the new item.
      • This means it is now less likely for a player to need to take a leap of faith down a path that they apparently cannot return from.
      • Note, however, that the return path back to the Ship doesn't necessarily need to be the same as the path to the item from the Ship. This means that in some cases a leap of faith can still be required, unless the player has enough map information to either identify or rule out the possibility of a return path back to the Ship with their current items.
    • The structure of the spoiler log is updated: consistent with the new placement algorithm, for each key item a possible route is indicated for how to get from the Ship to the item and back.
    • Various quirks of the old algorithm are eliminated:
      • Key items are no longer biased to be placed in rooms with obstacles such as Big Pink.
      • It should no longer happen that extra unnecessary key items are sometimes dumped right at the beginning of the game (which occasionally happened before).
  • A new item placement strategy "Semiclosed" is added:
    • This is similar to "Closed" except it does not have the same tendency to withhold Energy Tanks and additional Supers & Power Bombs (only the first Supers and PowerBombs).
    • See the updated descriptions of all three item placement strategies.
  • When going down Warehouse Entrance elevator, an elevator map tile is revealed which was previously missed.

Version 27 (2022-01-08):

  • Enable Bowling Alley chozo during escape (to be able to activate bowling).
  • Adjustments to escape timer, which overall make it more lenient:
    • Make corrections to distances for rooms where a straight-shot path is not possible.
    • Simplify the computation to assume a speed of 2.0 seconds per unit of map-tile Manhattan distance on Expert settings (eliminated an upper-confidence limit calculation that was used before).
    • Adjust the difficulty presets so that the default escape timer multipliers align with resource multipliers (with Expert now having a multiplier of 1.0).

Version 26 (2022-01-06):

  • Fix the far right platform in Mother Brain Room to be solid tiles instead of slopes, to avoid the possibility of falling through the tiles and being trapped by running into the room (since the attempted fix in Version 19 didn't go through).
  • Fix the area names in the spoiler log.
  • Logic updates from sm-json-data (diff).

Version 25 (2023-01-04):

  • Arrows on the pause menu map are colored according to the destination area:
    • Dark gray = Crateria
    • Green = Brinstar
    • Red = Norfair
    • Yellow = Wrecked Ship
    • Blue = Maridia
    • Light gray = Tourian

Version 24 (2023-01-03):

  • When Samus dies, skip game over screens, reloading immediately from last save.
  • Reload from last save during gameplay by pressing L + R + Select + Start.

Version 23 (2023-01-03):

  • A couple improvements applicable before acquiring the area map:
    • When using elevators, mark its tiles explored (fixes a gap in map tiles which previously affected elevators).
    • When crossing areas, mark the corresponding arrow tiles as explored.
  • Restore the vanilla message box font (which was unintentionally changed in Version 19 as a side effect of the new map patch).

Version 22 (2023-01-02):

  • Fix crash that happened in Version 21 when picking up X-Ray.

Version 21 (2023-01-02):

  • Escape timer is tailored to the seed based on the distance back to the ship.
    • A multiplier is available under "Customize skill assumptions" to adjust the escape time.
    • An option is available to include the extra distance needed for saving the animals.
  • Samus collects & equips all items (excluding beams, ammo, and tanks) when acquiring Hyper Beam.
    • Items collected in this way do not count toward the "rate for collecting items" shown after the credits.

Version 20 (2023-01-01):

  • During the Kraid, Draygon, Ridley, and Golden Torizo fights, restore gray door locks, making it no longer possible to run through the room without defeating the boss.
    • The door through which you entered is kept blue, so it is still possible to back out of the fight.
  • Allow Samus to move freely during the Kraid fight (instead of being constrained to the left half of the room during the first phase), making it possible to exit to the right if you entered from that direction.
    • Note: The camera is still constrained to bottom screens during the first phase of the fight, which means it is possible for Samus to go off-camera here.
  • During the escape, allow passage through the Acid Statue room (by spawning the Acid Chozo "enemy" that stopped spawning in Version 19).

Version 19 (2022-12-30):

  • During the escape, enemies and bosses no longer spawn.
  • During the escape, entering Kraid's room no longer cancels the escape music.
  • Fixed glitched graphics when pausing during Kraid fight (caused by map changes in version 18).
  • Fixed some issues with the Mother Brain room:
    • Prevent (non-existent) door from closing when entering the room from the left.
    • Fixed the far right platform to be solid tiles instead of slopes, to avoid the possibility of falling through the tiles and being trapped by running into the room.
    • During the escape, the escape door on the left is now always open.
    • During the escape, the invisible spike tiles where Mother Brain used to be are now gone.
  • Corrected a few map tiles: right door in Fish Tank, item dot in West Ocean, and passage in Green Hills (errors in version 18).
  • The map station on the title screen is animated.

Version 18 (2022-12-29):

  • Improvements to map/mini-map:
    • Doors are shown as 2-pixel-wide openings (vs. as solid walls in vanilla).
    • False walls/passageways within rooms are shown as 4-pixel-wide openings (vs. as solid walls in vanilla).

Version 17 (2022-12-27):

  • Music is based on map area! (This causes some glitches with sound effects which can be fixed later.)

Version 16 (2022-12-26):

  • Tech is partially cleaned up and grouped by difficulty for easier navigation.
  • Logic updates (diff).

Version 15 (2022-12-26):

  • Refining the behavior introduced in version 10 on how Phantoon's Room is placed:
    • Phantoon's Room will always be two rooms away from the Wrecked Ship Map Room (which is as close as possible).
    • The Wrecked Ship Save Room will always be in the same area as Phantoon's Room and the Wrecked Ship Map Room.
    • These rooms no longer have any tendency to be in a smaller area.
    • They can still be in an area with any name, including possibly Crateria.
  • Bugfix: Include Frog Savestation in the algorithm for balancing save stations.
  • Include good farm rooms (those with 5x Gamet spawns) in the algorithm for balancing refills.
  • Add "Map Rando" to the title screen.

Version 14 (2022-12-24):

  • With the rolling save functionality introduced in version 13, also advance the current save slot. This ensures that after a reset the default save slot to load will be the one most recently saved.

Version 13 (2022-12-23):

  • Supers now do double damage to Mother Brain 2.
  • Saving at a different save station from the last save will advance to the next slot before saving (wrapping back to slot 1 if the last save was on slot 3).
  • Fix graphical glitches that sometimes occurred when leaving Phantoon's Room before defeating Phantoon.

Version 12 (2022-12-23):

  • Fix an issue that caused new games (other than the first new game) to start at the wrong save location.
  • Fix graphical glitches that sometimes occurred when leaving Crocomire's Room before defeating Crocomire.

Version 11 (2022-12-22):

  • Using a Missile Refill station refills all ammo types: Missiles, Supers, and Power Bombs.
  • The current tile can be un-explored (i.e., turned back to black/blue on the map) by pressing Angle Up and Item Cancel simultaneously. To be effective, these inputs must be held while exiting the tile, since otherwise the game will immediately re-explore the tile.
  • Max ammo is shown in the HUD.
  • Restore rising acid in Tourian Escape Room 4 (unintentionally removed in version 8).

Version 10 (2022-12-21):

  • Replace the special behavior for Wrecked Ship introduced in version 9 with the following instead:
    • The Wrecked Ship Map Room and Wrecked Ship Save Room will always be in the same area as Phantoon's Room.
    • The area with Phantoon's Room will tend to be smaller than the other areas.
    • Note: Phantoon's Room can once again be in any area, including Crateria.
  • A new "-config.json" file is added to the returned ZIP, containing details about the version, random seed, and difficulty config used to generate the ROM.

Version 9 (2022-12-21):

  • Spread out the distribution of Save Room and Refill Rooms more evenly.
  • Add special behavior for the Wrecked Ship area:
    • Phantoon's Room will always be in Wrecked Ship.
    • The Wrecked Ship Map Station will always be in Wrecked Ship.
    • Wrecked Ship will tend to be smaller than the other areas.
  • Various corrections to the logic used for item placement (diff).

Version 8 (2022-12-19):

  • Add blue door in Tourian Eye Door Room, removing Gadora graphics.
  • Remove explosions & shaking in Tourian Escape rooms when not in escape sequence.
  • Restore sandfall layouts to be more similar to vanilla game, with only minimal changes to ensure safe transitions.
  • Remove the wall that spawned when entering Tourian Escape Room 1 from the right.
  • Set up door-specific FX correctly (applicable when entering rooms through a certain door):
    • Rising Tide left door: lava rises
    • Volcano Room left door: lava rises and room is heated
    • Speed Booster Hall right door: lava rises if Speed Booster is collected (Note: only happens until completed once, and the lava will never rise or be high when entering from the left.)
    • Acid Statue Room bottom-right door: acid is lowered
    • Amphitheatre right door: acid is raised
    • Climb bottom-left door: disable door-specific FX from the vanilla game, to prevent the lava from rising when entering from Tourian Escape Room 4 (except during the escape).

Version 7 (2022-12-18):

  • Map station tiles are visible from the start of the game.
  • Spoiler log is simplified; areas and a summary section are added.
  • Fixed bug in West Ocean that caused Tripper graphics to be messed up and G4 statues sounds to play.
  • Fix Wrecked Ship Save Room, which had a broken map instead of a usable save station (bug introduced in version 6).
  • Minor graphical fixes to map: fix external wall in Lower Norfair Firefleas Room, and remove an item dot from Big Pink that wasn't supposed to be there.

Version 6 (2022-12-17):

  • Upper Tourian Save Room is replaced with a map station.
  • Entering Tourian First Room no longer gives the area map.
  • Each area gets exactly one map station.
  • Cross-region arrow markers are added, becoming visible after getting the area map.
  • Fixed a problem where the new tiles (e.g., the concentric square map tile) overwrote water graphics.

Version 5 (2022-12-16):

  • Fixed graphics after leaving Kraid.
  • Unlocked camera in Spore Spawn Room so that entering from the right with Spore Spawn alive does not glitch the graphics.
  • Fixed graphics when entering Shaktool Room from the right (before Shaktool finishes digging).
  • Changes to make the in-game map more informative (more to come soon):
    • Refill stations (and the Ship) are marked by "+"-shaped tiles.
    • Map stations are marked by concentric square-shaped tiles.
    • G4 bosses and Mother Brain are marked by "X"-shaped tiles.
    • Items are consistently marked by a dot (and only tiles with an item have a dot).
    • Walls within a room are now consistently one pixel wide on the map.
    • Walls between rooms are now consistently two pixels wide on the map.
  • Added a description of Open/Closed item placement, and a link to the new Discord server.

Version 4 (2022-12-14):

  • Mother Brain rainbow beam no longer drains ammo (in case ammo is needed in the escape).
  • Mother Brain is marked defeated after the Mother Brain fight, so that if the player re-enters Mother Brain room Mother Brain will not spawn again.

Version 3 (2022-12-14):

  • Stop Crateria map from getting messed up when save station is used.
  • Skip map screens in file select. This was originally a temporary change for debugging the save map problem, but seemed worth keeping as a tiny quality-of-life change, making it faster to restart after resetting.

Version 2 (2022-12-13):

  • Fixed left door entrance to Crocomire Room and Mother Brain room.
  • Disabled demo (which was broken).

Version 1 (2022-12-11):

  • Initial release
1 Technically the planet is awakened by opening any gray door locked by an enemy kill count (which does not include gray doors locked by boss kills). In the vanilla game, such gray doors spawn in the Pit Room when entering with Morph and Missiles but are also in other rooms (e.g., Spore Spawn Kihunters, Brinstar Pre-Map Room). In Map Rando, at least for now, all gray doors are removed except in the Pit Room, making the Pit Room the only place where the planet can be awakened. Note that Pit Room also has an item that only spawns when entering with Morph and Missiles (regardless of whether the planet is awake).