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Legend of Zelda / Metroid Crossover

This is a crossover (aka combo randomizer) for the original NES Legend of Zelda and Metroid games. It is very much inspired by the excellent Super Metroid / Link to the Past combo randomizer. 

The randomizer shuffles items from both LoZ and Metroid across both games, and allows gameplay to switch from one game to the other, via special exits added to each game. This creates a unique challenge where you will have to transition from one game to the other several times to obtain all the items needed to complete both games. While items are randomized, this project is currently focused more on the crossover aspect and less on the randomization aspect. More randomization features will be added over time, however, there are already very good LoZ-specific and Metroid-specific randomizers out there, and this project is not intended to compete with them. 

Note: Like any piece of software, this may contain bugs to be discovered. I have no "team" so I must rely on community support to help find them. When a bug is reported, I try my best to get it fixed within 24-48 hours. 

Thank you for your patience and understanding. 


  • The game starts in Legend of Zelda in the normal start location.
    • You start with some rupees and bombs, since your trusty wooden sword is probably randomized away.
  • Major equipment and upgrade items from each game have been randomly shuffled across both games.
    • This is dependent on a random seed value, so each time you play, the arrangement will be different. 
    • The seed used can be configured, so multiple people can play the same seed if desired. 
  • Certain item counts have been adjusted. 
  • The randomizable items are:
    • LoZ:
      • Wooden Sword
      • White Sword
      • Magical Sword
      • Recorder
      • Blue Candle  (there are 3 in the game, same as LoZ)
      • Red Candle
      • Regular Arrows  (there are 3 of these -- one of the normal 4 have been replaced with a bomb upgrade instead)
      • Silver Arrows
      • Bow
      • Magical Key
      • Raft
      • Stepladder
      • Magical Rod
      • Magic Book
      • Blue Ring
      • Red Ring
      • Bracelet
      • Letter
      • Regular Boomerang
      • Silver Boomerang
      • Heart Containers  (13 of these)
      • Bomb Upgrades (have been turned into items -- there are 3 in the game instead of 2)
      • The 8 Triforce Pieces
    • Metroid:
      • Morph Ball
      • Morph Ball Bombs
      • High Jump Boots
      • Long Beam
      • Wave Beam  (2 of these)
      • Ice Beam  (2 of these)
      • Varia Suit
      • Screw Attack
      • Energy Tanks  (8 of these)
      • Missile Upgrades (20 instead of 21)
      • Totems of Kraid and Ridley
        • New items that have been created for this crossover.
        • These are required to raise the statues to enter Tourian.
  • If multiple ranks of an item exist, that item will never be overwritten with the weaker version of that item (for example, if you have Red Candle, and pick up Blue Candle, you will retain Red Candle).
  • If progressive swords are enabled, you will still see whatever sword was randomized into a certain location, but it will end up assigning you the next best sword. 
  • If you already have ice beam, wave beam items will re-spawn and if you already have wave beam, ice beam items will re-spawn.
  • By default, all items are guaranteed to be obtainable, even those not required to finish the game. 
    • This can be disabled in the settings file, so only the minimum items required are guaranteed to be available. 
  • Exits are inserted into each game, which allow gameplay to transfer from one game to the other.
    • Exits from LoZ to Metroid are added to four randomly selected locations on the overworld.
    • Exits from Metroid to LoZ are new doors added to these areas:
      • Brinstar (two doors are added)
      • Norfair (one door is added)
      • Kraid's hideout (one door is added).
      • Ridley's hideout (one door is added).
      • Also, taking the escape elevator from Tourian after defeating Mother Brain is an exit -- it sends you directly to Spectacle Rock.
  • Exit to entrance connections are randomized.
  • Defeating Mother Brain is required before entrance to Level 9 is granted (in addition to collecting all Triforce pieces).
  • Once Mother Brain is defeated, access to Tourian is no longer available. 
  • The games are (in theory) guaranteed to be beaten given the random item arrangement created.
    • It does this by applying a seed and testing the results against a constraint solver.
    • Let me know if you run across an unsolvable seed.
  • No special techniques or glitch exploits should be required to finish (such as infinite bomb jump or door glitching).
  • Some game enhancements:
    • Legend of Zelda:
      • When continuing after death, half of your maximum hearts are restored (configurable).
      • Item pickup fanfares are skippable.
      • NPC dialogs can be sped up.
      • While paused, the map will show dots in locations where you have not obtained the randomized item yet, and flashing dots where the exits are located. 
        • These can be disabled
    • Metroid:
      • When continuing after death, half of your maximum energy is restored (configurable).
      • Mini-map of areas explored.
      • While paused, the map will show dots in locations where you have not obtained the randomized item yet, and flashing dots where the exits are located.
        • These can be disabled
      • Fading-in of Samus is skippable.
      • Item pickup fanfares are skippable.
  • Automatic state saving and loading:
    • When stopping the script, the current global state for the current seed is automatically saved.
    • The next time you play -- if you use the same seed, the previously saved global state is restored. 
    • This way, you don't have to play the entire seed in one session. 
    • So, if you plan on multiple sessions, be sure to record your seed somewhere!


  • A fairly recent build of FCEUX (I've been developing against the build dated June 2, 2018) is strongly recommended.
    • The latest official release (2.2.3 / July 28 2016) is not compatible, as the project requires run-time ROM writes to work correctly, and that release of FCEUX has a breaking bug in this area. 
    • Bleeding edge win32 builds of FCEUX are available here: https://ci.appveyor.com/project/zeromus/fceux/build/artifacts
    • If you are using a version of FCEUX without the ROM writing bug fixed, you will see an error message when you attempt to run the script. 
    • Feel free to try an older version (like 2.2.2), as I'm not sure when the ROM writing bug originated, but compatibility with older versions is unknown. 
  • A Legend of Zelda ROM image
  • A Metroid ROM image

No, I don't know where you can get ROM images.

Download lozmx1.22.8.zip here

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Help wanted!

I'm looking for people to help with testing. If you're interested, let me know on Discord!