I'm writing this guide under the assumption that you're already familiar with the ins and outs of how the game functions. Bob's Brain will kill you, don't pick up Cursed Eye unless you hate yourself, Devil Room chance is dictated by Red Heart damage, yadda yadda yadda.

If you're a newcomer to the game as a whole, I highly recommend consulting the official Wiki, which I've linked here, if you can.

https://bindingofisaacrebirth.fandom.com/wiki/Binding_of_Isaac:_Rebirth_Wiki

Or, if you hate Fandom and its insane amount of ads, just play the game yourself and figure it out on your own! It's a part of the process, in my humble opinion.

The purpose of this guide in particular is to demonstrate how Online Play works and what you can do to make the experience better (or worse) for strangers you find yourself with or with friends who own the game.

Got it? Tear ducts primed and ready to sob as a collective group of 4 onto the horrors of the basement? Great. Let's do this.

First, it's probably worth mentioning that regardless of who you play with, you will probably be lumped into situations with people who aren't as familiar with the game, which can lead to agonizing, hilarious, or agonizingly hilarious scenarios.

Something worth noting is that separate from local co-op, you are given an active camera that remains relative to your position at all times, meaning that without the burden of a single screen, you can tend to your own business as much as the other players can, and take as much time as you need to process things and kill enemies.

Isaac has a robust number of characters to choose from, ranging in play style, appearance, level of sadism the developers had towards the playerbase when they came up with them, et cetera.


It's probably worth noting that certain characters will function well with others, and others will be the most likely contenders of dying horribly early on into the run and being left for dead.

Beneficial Characters:

Azazel:






Azazel is the most likely contender for the best "boring but practical" character the game has to offer. The dude can fly, is extremely powerful, and his short range can be offset by picking up Range Ups.











Tainted Lilith:







Tainted Lilith is also an incredibly powerful character whose sheer range and damage make up her inability to fly. Even as a post mortem co-op baby, her fetus-based melee attacks still do a pretty good chunk of damage to bosses and enemies alike.










Tainted Isaac:








Tainted Isaac is an utter double-edged sword in the face of co-op due to his ability to automatically reroll/double the quantity of item pedestals, but only for those who time it right. For people who don't know how he works, mistiming interactions with item pedestals is a crapshoot in of itself. In my opinion, the upsides outweigh the downsides.










On the flip-side, characters with limited health pools or mechanics that clash with the spirit of co-op such as Keeper, Blue Baby or the Lost may not jive well with the rest of the gremlin children and will probably die first.

Within the semi-limited range of actions you can perform within Isaac, there's a few ways in which you can telegraph to other Basement-dwellers what to do and not to do.

I've prepared this handy-dandy infograph made by my friend Poko to showcase some of these!


Pointing: Shooting tears in any given direction can signify to your comrades to divert their attention to where you're shooting. Whether it be to point to a tinted rock, to show off where you think a secret room is, really there's a lot of room for interpretation here.

Drop: Holding the Ctrl key or trigger in the game itself can drop your held trinket and card/pill. You can inform other naked babies to do this by violently face-planting into the side of a bottom wall, most effectively within a smaller room.

Boo-yah! To celebrate a victory or collective achievement of some sort, use WASD or the control stick to spin around in a circular motion. Soon, you'll all look like a buncha idiots walking around in circles together. If that's not the essence of online multiplayer, then I have no idea what is.

No... If you don't want your companions to do something irrational, or take something you want, walk from left to right to emulate the motion of nodding your head sideways. Just be sure not to walk into any hazards while doing this or you'll probably feel like a ding-dong.

Yes! If you want to agree with something your fellow infantile spelunkers are doing, walk up and down to simulate the motion of nodding your head up and down.

Go ahead! In situations where you've come face to face with an item or something that a particular player could benefit from, you can walk away from it to let them know that it's all theirs, or alternatively, standing idly could accomplish a similar vibe.

Whether you're a newcomer or a long-time veteran of the escapades of the tortured child, hopefully reading this guide will give you a proper idea of how to behave alongside both strangers and friends online! Treat others how you want to be treated, and share the spoils of your efforts as a collective!

Thanks for reading!