Category Archives: Editroid

Editroid 3.7

Version 3.7 of Editroid is available. You can get it at’s page for Editroid. Version 3.7 adds support for multiple ASM files to manage more complex ASM hacks.

Editroid 3.6

A new version of Editroid has been released with some bug fixes (namely a bug that prevented certain screen-load code from running). Grab it from the RHDN Editroid page. Everything should work the same as Editroid 3.5, except fewer bugs.

ASM Hack: Elevator to Same Level

Here is a nice, small hack that allows you to add an elevator to Metroid that, rather than bringing the player to a different level, brings the player to a different part of the same level. This hack is very unlikely to work with any other hack that involves ASM since it uses the memory […]

Editroid 3.5

Time to release a new version of my Metroid editor. This version allows you to add ASM to each screen that will run when the screen loads. It includes a built-in assembler so you can do everything right in Editroid.

Editroid: Enemy Slots

This is just a quick explanation of a quirk in enemy placement in Metroid.Enemy Slot The game engine is capable of showing up to six enemies at a time. Each enemy is stored in an “enemy slot” in memory. The unusual thing about the enemy slots is is that rather than having the game load […]

Metroid Hacking Resources

This is my attempt to collect and catalog useful resources for Metroid hacking. If anyone wants to make an addition, feel free to tell me in the comments.

Editroid 3.0

Editroid 3.0 (beta) is ready and willing to satisfy all your Metroid hacking desires! You can download the editor or the source code.

Metroid: Wavy-Ice

I’ve decided to share my simple Wavy-Ice hack. It allows the player to combine the wave beam and ice beam in Metroid. Note that this only works on a ROM expanded by Editroid 2.1.

Metroid Tuner

So I made this thing to edit Metroid (NES) music data, and I named it “Metroid Tuner,” because I didn’t feel like trying very hard to come up with a good name. Metroid Tuner dumps and inserts music using a relatively simple text-based format.

Doors With Editroid

I know I was pretty confused about how doors work when I started messing with Metroid, and it’s been a recurring question. The trickiest part is scrolling, but I’ll go over a couple other points, too, so here’s the scoop.