The Birth of Rebirth

Hello, I’m not Edmund McMillen. I’m Tyrone Rodriguez, part of Nicalis—the developer/publisher working with Ed on The Binding of Isaac: Rebirth. I’ve taken over the blog for today’s update, which will have a focus on console along with new information seeds.

You probably don’t know who the hell I am. I’ve worked on other games like Cave Story and more recently 1001 Spikes.

To tell you what you should expect on PlayStation 4 and PS Vita I have to take you back to how we started. Isaac Rebirth was originally envisioned as a 3DS game back in 2012 by Ed and I. With that said, the native resolution of The Binding of Isaac was going to be 400x240. However, some things had to be changed once we increased the scope of the game and went the way of PlayStation 4 and PS Vita instead of 3DS.

For PlayStation 4, PS Vita and even PC the native resolution is 480x272. Why such an odd resolution? Aside from being the most versatile resolution across PC and most consoles with semi-16:9 screen, this resolution is a good fit for pixel art AND lets us we get everything we need on-screen in Rebirth.

The differences between the PS Vita and PS4 versions will be generally visual/superficial. The PS Vita DOES NOT have the CPU/GPU of the PS4 and that means not all the crazy special effects and shaders will be in the PS Vita version. Visually, there’s A LOT going on with Rebirth and on Vita we’ve prioritized the game feeling good and being fun. Anyone who’s played the flash version of Isaac can tell you trying to play at 10fps is anything but fun. That doesn’t mean the Vita version won’t look awesome, it just means that if you want all the visual effects, you’ll be play on PS4 or PC. If you want to play anywhere, you’ll be playing on Vita.

But what you will get with the PS Vita (and PS4) is a console version of Rebirth that will run at 60 fps (the original flash version was 30 fps) with analog/digital control support and fully configurable control mapping. So now everyone will be happy—even southpaws.


PlayStation 4 Control

By default, you’ll move and shoot using both digital and analog controls. That way you can play with analog movement and analog firing, analog movement and digital firing or any combination. The pill, item and bomb are all, by default, set to the shoulder buttons.


PS Vita Control

The PlayStation Vita is “missing” two additional buttons, but we’ve found a decent work around. The general configuration will be similar to PS4 in that, by default, both digital and analog input work for movement and firing. The shoulder buttons are used for Pill and Bomb and the Select button is used for Item.

Changing map size is handled with the front touch screen. We’ve put a border around the touch screen so that you don’t activate the larger map by accident. There is no use for the rear touch because it’s not precise.


Because The Binding of Isaac: Rebirth has a fully configurable button setup. You can literally set the buttons as you like. And we’re certain that you’ll change them around almost instantly. For example, on Vita, if you know you only play with analog movement and firing, then you can move all the vital inputs to the face buttons and not have to mess around with the shoulder buttons.



So you’ve heard Ed and I mention unique seeds for Isaac Rebirth, but we haven’t told you everything, not entirely. As part of today’s update, let’s give you some more information on them

What you probably do know is that in the original Binding of Isaac (that is, the flash version), floors were produced randomly the moment you entered them. In Rebirth, the seed determines every floor layout, room, enemy and item in the run. There are 2^32 - 1 or 4,294,967,295 possible seeds—over 4 BILLION combinations.

And what this means is that if you’re playing and find a really fun or challenging run, you can find out the seed, write it down and replay it later or send it to your friends.

If you and your friend have a different set of items unlocked, you will mostly see the same items in the same places, but any items the seed generates which you haven’t unlocked will be replaced with one you do have.

However, you will not be able to unlock anything while you are playing a seeded run, so you can’t cheat to unlock everything easily.

Lastly, the seed is 8 characters in the format ABCD EFGH with all alphanumeric characters allowed except the letters I, O, U, and V—because those look too much like other letters.

Follow me on twitter @tyronerodriguez or don’t (I’ll be crying over here)

The Jar has appeared in the basement!

This week we will be spoiling another new item, this time it comes in the form of a usable item found exclusively in stores… the Jar.


The Jar is a new item that really sticks out for me due to how unique it actually is. it essentially acts as 4 empty container hearts for you to fill up and use as you wish, you just need to find the hearts to make it work.

advanced players will find a whole lot of uses for this item, its not the holy grail of breaking but ive found some pretty great exploits using it in tricky ways.


the game is currently nearing completion and we are in the heavy tuning/polish phase. maybe next week you will see the 1st actual video footage of the game in motion? or maybe tyrone will help me out with a little console info update? who knows.. maybe ill be dead by then. 

Trinkets and Worms and Maps… oh my?

one of the most common questions i get asked a ton on tumblr is are any old items from isaac being removed/replaced? and the answer is yes.. but most are just getting moved around.

an item that a lot of people hated in isaac was the wiggle worm.. but it was so cool… i didnt want to get rid of it! so one of the 1st things i did in rebirth was had it moved down to a trinket. the wiggle worm is one of 18 new trinkets in rebirth, and one of 6 worm type trinkets that change how your shots move/act once you shoot them.

this is the Round worm trinket in effect. (am i the only one who played festers quest?)



but the wiggle worm isnt the only item that has moved around, the Polaroid has been now moved up to an item (i hope yo are happy!). there are a few subtle changes to old items and even some visual make overs (max’s head is now crickets head, based off our newest cat cricket).

another big make over in rebirth is the map.

many of you have been bitchin about it.. assuming thats all there is to work with.. but thats just the MINI MAP! nice and out of the way. i hated how clunky the hud was before so i wanted thinks to be as neat and tidy as possible in rebirth.


as you can see in rebirth pressing the “map” button once will display the fullsized map on the upper right of the screen, this can be toggled on and off and holding the map button will make the full map opaque.

another use for this new button is something many advanced players have requested a lot, if you press and hold map for a few seconds isaac will empty out his pockets, meaning all held pick up items (trinkets, cards, pills) will be tossed to the ground around isaac… but that tick isnt coming off!

next week ill talk more about the shop item pool and reveal a shop exclusive item… ill give you a hint on what it is, you should never stick this item in your butt.. but i know of one guy who has….


this was too amazing to not share here.
art by Angela Siphaengphet

this was too amazing to not share here.

art by Angela Siphaengphet


This week i bring you yet another fantabulous track from the binding of isaac: rebirth soundtrack, the title screen track “Genesis” by Matthias Bossi (featuring Carla Kihlstedt)

you can kinda get a sense of the audio thematic switch im going for with rebirth when listening to this track compared to the old one, im very happy with the vibe this track has going for it.

as these updates unfold over the coming months im going to be holding back more.

as i mentioned in the last update rebirth will feature a TON of new content.. and i really dont want to spoil too much before you all can experience it first hand. 

that isnt to say the next update wont be a big one.. just expect some out of left field updates in the future ;)

till next week!

(insert size matters joke here)

its time to talk about size! 

ive said many times that rebirth will be much larger than the original + the expansion were, put together, but i thought it might be time to talk more in depth about exactly how.

so 1st off the base game + wrath of the lamb boasted 198 items, currently rebirth features well over 450 items, not to mention a lot more common item pick ups like the lil battery, black heart, new card types and a lot of double items like the key ring.

Rebirth will also feature over 50 new enemies (not counting bosses) and will also include the addition of color specific champion variations that each will have their own new way of killing you.

Rebirth will feature 15+ new bosses, but a new (and very fun) addition to these bosses are the “double trouble” boss fights, kind of like a curse for the boss rooms that forces you to fight 2 previous chapter bosses at once in a larger sized room.


But my personal favorite HUGE addition to rebirth is the number of new rooms and the control i now have over each one.

for those that dont know, isaacs levels are composed of randomly selected rooms placed in a map that forms a logical and completable floor. each of these rooms that can be placed into a floor i design in a level editor.

the old game featured 150 rooms per chapter (basement, caves, depths, etc)… but Rebirth will boast well over 500 rooms per chapter (counting large rooms as 1 room). 

this huge addition of levels makes things a lot more fun and interesting to play, on top of all the new rooms the new level editor allows me to do a lot of stuff i wasnt able to do before. i can now design rooms where doors are turned off, this makes it so i can create more dramatic and cool looking areas. 


rooms now also feature a rarity slider, so i can design a room that is as rare to generate as the error room is to find… but on top of all of this im also now able to make anything in the room have a more rare alt to it. a good example being this room, there is a very small chance those metal bricks turn into rocks so the black heart becomes accessible.. 


these aspects might seem minor, but they allow for a seemingly endless game, to REALLY appear endless… you can only remember so many room layouts :)

finally, rebirth will also feature 5 new special room types (like the arcade, sac room, devil room, etc) i wont be spoiling any of these so you can figure them out yourselves.. but they are all quite cool and im looking forward to reading about what you think the hidden purpose of each is…

i leave you with this…


Isaac, The Gathering!

Its time for a new item! this week… Mom’s Perfume!


This new “status effect” item is part of a cycle of new items that cause status effects on enemies, moms perfume causes “fear”.


there were some items that gave status effects to enemies, but this time we are doing it in a more interesting way, now the status effect isnt just a % chance, when a tear hits it does the effect.. now you actually see the tear with the effect on it when you shoot (note the yellow tears in the gif). on top of that each status effect will change the enemy visually, here is a poison effect + moms perfume + another new item… (ideal for an isaac build based around status effects)


there are quite a few pretty awesome new effects i cant spoil here… but im sure if you use your imagination you can come up with some.

but now on to the thing ive been wanting to talk about for almost 2 years but couldn’t. its somewhat isaac related seeing as i pulled a lot from its design (pretty abstractly though), but either way…



i honestly never thought id type those words. It has been a dream of mine for a very long time, see magic the gathering was probably one of the most important games in my life.. especially when it comes to game design. 

I got into MTG when i was 13 (94ish), my best friend AJ told me that i needed to see this card game that was like DnD, where you could summon demons and dragons to fight along side you. i watched these kids playing at the local boys club and when i saw Keldon Warlord hit the table i was floored… “he gets bigger the more creatures you have in play” AJ said. i was already thinking of amazing deck ideas based on the card that play a lot of little creatures so the warlord came out mega huge!… i was sold, i went to a comic shop and picked up a starter deck of revised (because unlimited starters were 4 bucks more!) and my love affair with magic was born.

2 years ago i was lucky enough to be one of quite a few other game devs to be asked to help design a card for the next core set, M15. i had a hobby of designing magic cards, myself and a few other game dev friends of mine actually designed a whole fake set of cards just for the hell of it one month.. so when i was asked to submit a few card ideas i went through my notes and sent in a cycle of cards i called “the children”.

the cycle was a series of 1 drop creatures in each color that were designed to be rare, think 1 drop titans. 

i cant find my notes for all 5, but the 3 i submitted to wizards were these.

Blue Child-


t: untap target land you control, you may only do this when its not your turn 


Green Child-


Flash, when this creature takes damage put a +1+1 counter on it


Black Child-


T: pay 1 life put a +1+1 counter on this

T: remove X counters from this to do X damage to target creature or player


I really liked the Blue Child a lot, but it wasnt an ability wizards wanted to print in a core set and leaned more towards the Green and Black cards. in the end i decided to focus on the black 1 drop because i felt it was a lot more interesting.

the cards name became Cruel Sadist, a psychotic child that feeds off the player to grow stronger then unleashes it on creatures or players, i had pushed the idea of the card being a succubus or vampire type creature that would drink your blood and spit it at stuff, but wizards liked the idea of a crazed child assassin a lot more.

the card was designed to be kind of like a
Guul Draz Assassin that could possibly protect itself a bit earlier and had more options late game. i really like reactionary decks, i could see myself playing it in a blue black control deck that waited till the eot with a counter spell, but if nothing was played then i put a counter on my guy to raise the threat. it could also be a great anti green card, killing off any early game mana elves and the like. 

i like cards that give me a lot of options, killing creatures, growing larger, damaging players or just being an agro 1 drop were all options so this was the card i wanted to push through.

sadly my design was a but too OP and needed to be taken down a few pegs. the design team played around with the card, adding a black mana to each of its abilities and even moving it down to an uncommon to see how it played there. There was a great deal of back and forth on the card but in the end this was the final design for Cruel Sadist.


Remind you of anyone?

Not exactly the micro titan i had planned, but im sure she will find a home somewhere. 

it was great working with the team, i learned a lot about the design process and how much testing actually goes into these sets.. i now understand why they make them 2 years in advance. its such a huge honor to have been a part in one of the best design games of all time and look forward to drafting the hell out of this set.



Be careful.. i don’t wanna lose this baby…

Ok, lets talk co-op.

as many of you know, one of the biggest and easily one of the most fun additions to Rebirth is local single screen co-op.. and here is how it works.

when you are playing isaac, a friend/mom/soul mate can join you by pressing start on the 2nd controller (or 1st controller if you are playing with the keyboard).. like so. 


as you can see, joining a game steals a container heart from the main player and spawns in a little floating baby, i had originally though of them as isaacs imaginary friends, but calling them babies is just more fitting.

when a 2nd player spawns in, both players damage/tears are lowered to balance things a bit, but every aspect of whatever items isaac has at the time of spawning are applied to the baby, including usable items. 


P1 still controls when items are used.. so its good to communicate and strategize.

but it wouldn’t really embody the isaac spirit without some element of random generation… that’s where the baby generator comes in.


each time you start a new game, or a baby dies, when p2 joins a game their baby avatar is randomly picked from a very large list of babies.

a lot of the baby forms are just cosmetic, but there are also quite a few “special babies” that each come with their own abilities.

but a 2nd player is OP as is! doesnt adding special babies make things even more of a walk in the park? well much like pills, every special baby has a “cursed” counter part. so there is just as much of a chance in spawning a baby that will randomly spawn a troll bomb every 1-2 min. as getting a baby that heals p1 when it dies.

aside from normal, special and cursed babies, rebirth will also feature a full set of unlockable babies that are tied to specific characters aka maggy will have a higher % chance of generating a maggy themed baby once you have unlocked it. 

here is a little assumed faq for co-op.

-co-op is local play only.

-co-op IS NOT online in anyway (aka you can only play with someone in real life next to you)

-p2 can only join of p1 has more than one container heart.

-p2 can steal life from p1 by pressing start, but cant steal any life if p1 has only one heart left.

-there are NO co-op related requirements to gain platinum god. 

-there will be some co-op related achievements.

-the game will be balanced so co-op wont be as OP as you would assume

-p2 flys, but cant pick up any items.

-once p2 dies when they respawn their baby is randomly chosen again. 

-p2 can leave play giving p1 back their life at any time, but if they spawn back in they will be using the same baby. 

-its a lot more fun that you would imagine :)

Danielle and i have been playing co-op a ton since it was implemented and i can honestly say it totally changes the experience, its a great addition for anyone who has a friend/significant other to play with and is an awesome way to get new players into the game.


what do you want to see next week? new item? new enemy? or new room type? new challenge? or something totally different? reblog and tell me, you just might get lucky…    

Polygon Binding of isaac Rebirth interview E3 ultra edition! 

The Binding of Link!