The Binding of Isaac: Rebirth Mods
The Binding of Isaac: Rebirth is a roguelike top-down shooter that was released in 2013. Since then, it has received several major content updates in 2015, 2017, 2021, and 2024.
TBoI has a thriving modding community on Steam, to which I contributed some of my own works. I originally published most of them from Jul ’21 to Jul ’22, but updated and republished most of them in Feb ’25 to add additional content and patch bugs.
Ultra Headless Horseman
“A Headless Horseman has appeared in a Broken Home…”
Ultra Headless Horseman was the first original mod I’d made since Ultra Conquest, publishing it in May ’25. Since then, I’d built up quite the repetoire of skills, as well as higher standards for publishing. As such, this project involved more sprites, more animations, and more programming. Thankfully, I’d already figured out a decent chunk of specifics thanks to Ultra Conquest, so the only difficult parts were things unique to Ultra Headless Horseman, like the head being a seperate entity in one attack. Otherwise, I did try to record myself for SFX, but the audio was too low-quality for my liking. As such, I just used SFX from the other horsemen like Ultra Conquest.
Ultra Headless Horseman’s Trailer
Ultra Conquest’s Trailer
Ultra Conquest
“A Forgotten Horseman has appeared in a Broken Home…”
Ultra Conquest was my big project to work on during Summer Break of ’22. I made all of the sprites, animations, AI, and LUA code for actually setting the conditions for the boss to spawn correctly, as well as made the code easily changable for difficulty tweaking. I also modified things afterwards based on user feedback (namely, that it was too easy), as well as making it compatible with other mods.
The big rerelease update for this mod was adding the option to fight Ultra Conquest alongside the other four horsemen, no longer replacing Ultra Death. It did lose me compatability with another mod, but i feel like that’s a very small price to pay for such a requested feature.
Hit List
“Adds sprites of each character’s unlockables to the sticky note of every character. Also adds custom icons for both Greedier and Delirium/Void.”
This one was really tricky to implement; mods that change actual gameplay are limited to in-game stuff, not the menus, so I had to change only menu graphics and animations to be able to display unlockables for each individual character. I also had to make like a hundred-something tiny sprites for things that don’t have menu graphics, like trinkets and cards.
The titular Hit List
Dogma Costume
Dogma’s Truth
“Adds a new four-charge active item to the Angel and Greed Angel Pools called Dogma’s Truth!”
A lot of people requested a item-based version of the Dogma Lasers mod when it was first released, so this is my answer to that! It originally took me a while to make, as both room-based active items and lasers are tricky to work with.
The rerelease updates for this mod were patching numerous bugs that had to do with the item’s activation and deactivation, the item not working correctly with multiple players, and adding a chargebar for the laser if that option is enabled in the game’s settings.
Parallel Cloth
“The effect of the Parallel Cloth is simple: Any tarot card used will trigger both their normal and Reversed effects. This goes for both normal AND already-reversed tarot cards. This also stacks with Tarot Cloth!”
Simple mod, simple execution. I still REALLY want something like this to be added in via something like one of Afterbirth’s Booster Packs. Hit me up, Tyrone!
Parallel Cloth’s Effect
Comedy Incarnate
Epiphora Buffer Frames
“Epiphora now has 5 buffer frames (13 for Brimstone) where the tear multiplier doesn’t go away, meaning you can take your finger off the fire button to use both chargable and tappable items, then quickly press the button again to keep your multiplier!”
This was the first of my in-depth mods to get somewhat popular, and it was well-deserved; this was the one mod I was somewhat happy with prior to Repentance+ (the 2024 DLC)’s release.
The rerelease update with this one was actually a necessity, as Repentance+ changed how Epiphora worked, and so I needed to change my mod to compensate. Along with changing the effect to work with the new effect of Epiphora, I also took the time to patch up an issue with the mod in multiplayer.
Dogma Lasers
“Replaces the graphics and sounds of all player-spawned brimstone beams with Dogma’s static lasers!”
The original mod was just sprite and audio modifying; nothing too, too impressive there. With the remake, on the other hand, I actually used a script to replace the sprites and audio instead of the built-in replacement system. That way, I could only modify the player’s spawned lasers, which is what the intention behind the orignal mod was.
Thing is, the original version of this mod got popular. Like, really, REALLY popular. So popular in fact, that the guy that inspired me to get Isaac, Grayfruit, was actually using the mod for a while!
A Dogma Laser and a base-game laser
Viewership stats for the original mod as of 4/18/25