So, you’ve finally beaten Mom’s Heart. You’re feeling good. Then you see it—that little scrap of paper on the character select screen with a single, lonely heart drawn on it. Welcome to the real game.
The Binding of Isaac completion marks aren't just little stickers for your ego. They are the literal backbone of how you unlock the most broken, run-saving items in the game. If you aren't filling that post-it, you're basically playing a demo version of the 700+ items available.
Honestly, the sheer amount of stuff to do in Repentance is terrifying. We’re talking 34 characters (if you count the Tainteds) and 12 distinct marks for each. Do the math. That’s 408 marks. It’s a lot. But once you understand what each symbol actually stands for and how to path your runs to get five or six at a time, it stops feeling like a chore and starts feeling like a heist.
What Do Those Little Symbols Actually Mean?
If you're staring at the post-it note wondering why there’s a cent sign or a weird knife, don't worry. The game is notoriously bad at explaining itself. Each mark corresponds to a specific "end-game" boss or a timed event.
The symbols are fairly intuitive once you’ve seen the bosses, but for the uninitiated, here is the breakdown of what you’re looking at:
- The Heart: You killed Mom’s Heart or It Lives. This is your baseline.
- The Star: This is Boss Rush. You have to kill Mom in under 20 minutes to open the hole in the wall. It’s a sprint, and it’s usually where most runs die because you rushed and didn't build enough health.
- The Cross (Isaac): Beating the boss in the Cathedral.
- The Polaroid (Blue Baby/???): Beating the boss in The Chest.
- The Inverted Cross (Satan): Beating the boss in Sheol.
- The Negative (The Lamb): Beating the boss in The Dark Room.
- The Brimstone Sigil (Mega Satan): Opening that giant golden door in The Chest or Dark Room. You need the two key pieces from bombing Angel statues or some very specific items like Mr. ME! or Sharp Key.
- Hush’s Face: Beating Hush in the Blue Womb. You have to beat Mom’s Heart in under 30 minutes.
- The Cent Sign: Beating Ultra Greed in Greed Mode.
- The Red Cent Sign: Beating Ultra Greedier. If you beat Greedier, you automatically get the Greed mark too.
- The Crumpled/Tattered Paper (Delirium): Beating the boss in The Void. This portal has a random chance to spawn after major bosses, but it's a 100% guarantee after Hush.
- The Knife: Beating Mother in the Corpse. This requires the "alt path" (Downpour, Mines, Mausoleum) and finding the two knife pieces.
- The Note: Beating The Beast. This involves the "Ascent" sequence where you go backwards through the floors you just cleared.
Why You Should Stop Playing on Normal Mode Immediately
I know, I know. Hard mode is... hard. But here’s the thing: The Binding of Isaac completion marks have two states. If they’re black, you did it on Normal. If they have a bloody red outline, you did it on Hard.
If you get a mark on Hard, it automatically gives you the Normal mark. If you play on Normal, you’re eventually going to have to do the exact same run again on Hard to get the "Godhead" or "Death Certificate" unlocks. It’s a massive waste of time. Just bite the bullet. Hard mode in Repentance isn’t even that much harder in terms of enemy health; it mostly just tweaks shot speed and heart drop rates. You’ll get used to it in three runs.
Efficient Pathing: How to Get 7 Marks in One Run
You don't want to do 408 individual runs. That’s how you get burnt out. The pros (and the masochists who have three Dead God files) use specific routes to knock out as many marks as possible in a single go.
The "Power Run" Route:
- Reach Mom in under 20 minutes and clear Boss Rush.
- Reach Mom’s Heart in under 30 minutes and kill it to go to Hush.
- Kill Hush, then instead of going to the Cathedral/Sheol, take the portal to The Void to kill Delirium.
Wait, I missed some, right? If you’re really strong, you can actually go from Hush to the Cathedral/Sheol, clear the floor, go to the Chest/Dark Room, kill Mega Satan, and then hope for the 50% portal spawn to Delirium. It’s a gamble. But if it works, you just got Boss Rush, Hush, Isaac, Blue Baby, Mega Satan, and Delirium in about 45 minutes.
The Unlocks That Actually Matter
Not all marks are created equal. Some characters have terrible unlocks (looking at you, Tainted Blue Baby), while others are essential.
If you’re just starting your completion journey, prioritize Jacob & Esau. They are a nightmare to play. I hate them. You probably hate them. But beating the Witness (Mother) with them unlocks Damocles, and beating The Beast unlocks Birthright. These are top-tier, game-altering items.
Then there’s The Lost. You need all hard mode marks on him to get Godhead, which is arguably the most iconic item in the game. It’s painful, but the satisfaction of seeing that completed post-it is better than any drug.
Tainted Characters and the "Patchy" Post-it
Once you unlock Tainted characters, you’ll notice their completion marks look a bit different—they look like they’ve been drawn on a tattered, bloodied scrap of paper. The requirements are the same, but the unlocks are often "Soul" stones or "Reverse" tarot cards.
A common misconception is that you need to do something different for Tainted characters. You don't. Just follow the same bosses. However, the Tainted characters often have "grouped" unlocks. For example, beating Boss Rush and Hush on a Tainted character unlocks their specific "Soul" (like Soul of Isaac). Beating Isaac, Blue Baby, Satan, and The Lamb as a set often unlocks a specific trinket or item.
Actionable Next Steps for Your Save File
Stop wandering aimlessly through runs. If you want to actually "complete" the game, you need a plan.
- Check your unlocks: Look at your secrets menu or a checklist site to see which characters have the best items still locked.
- Force the Alt Path: Start practicing the Mother path. It’s the hardest content in the game, and you don't want to be learning those patterns when you finally have a "God Run" on a difficult character like Tainted Lost.
- Donate to the Greed Machine: You need 1,000 coins in the Greed machine to unlock the Keeper and eventually Greedier mode. Don't do this all with one character; the jam chance increases the more you use the same person. Rotate characters!
- Focus on the D6: If you haven't beaten Isaac with Blue Baby (???), do that right now. It gives Isaac his starting D6, which makes every subsequent run 10x more manageable.
Once you’ve cleared the "essential" items, then you can worry about the completionist grind for the sake of that 100% achievement. Just remember to breathe when Delirium telefrags you at 5% health. It happens to the best of us.