How to Unlock Tainted Characters in The Binding of Isaac: Repentance
A guide on Unlocking Tainted Characters in The Binding of Isaac: Repentance

Unlocking tainted characters in The Binding of Isaac: Repentance introduces a fresh layer of complexity and excitement. These alternate versions of existing characters feature unique abilities and challenges, enriching your gameplay experience. Here’s a step-by-step guide to help you unlock these fascinating characters effectively.

Step 1: Reaching the Home Area

To begin unlocking tainted characters, you must reach the Home area. This process involves acquiring Dad’s Note, a pivotal item that sets the stage for your journey to Home. To get Dad’s Note:

1. Defeat Mother in the Corpse area during a run.
2. Use The Polaroid, The Negative, or Faded Polaroid to open a special door.
3. Ascend through the floors you previously completed, revisiting old rooms.

During this ascension, you must tackle increasingly difficult challenges until you arrive at the Home area.

Step 2: Finding the Red Key

In the Home area, enter Mom’s Room and open the chest to retrieve the Red Key, your essential tool for unlocking tainted characters. The Red Key grants access to hidden rooms that house these characters. Keep in mind, the Red Key is only available during your first visit to Home.

For subsequent attempts, you’ll need an alternative: the Cracked Key. This is a modified version of the Red Key and can be created during your runs.

Step 3: Unlocking Tainted Characters

Once you have the Red Key, the process to unlock a tainted character is straightforward:

1. Exit Mom’s Room and stand in the hall.
2. Use the Red Key to reveal a hidden room.
3. Enter the room and interact with the tainted version of the character you’re currently playing.

Congratulations! The tainted version of that character is now unlocked and can be used in future runs.

Creating Cracked Keys

Since the Red Key is a one-time item in Mom’s Room, the Cracked Key is crucial for unlocking additional tainted characters. Here’s how to get one:

1. During a run, drop a trinket in a boss or treasure room by holding the appropriate button (e.g., Left CTRL on PC, R2 on PlayStation).
2. Obtain Dad’s Note and ascend.
3. Revisit the rooms where you dropped trinkets. The trinkets will have transformed into Cracked Keys.

With a Cracked Key, you can repeat the same process as the Red Key to access hidden rooms and unlock more tainted characters.

List of Tainted Characters

There are 17 tainted characters in total, each offering distinct gameplay twists. Some popular examples include:

• Tainted Isaac: Focused on strategic item management with limited inventory slots.
• Tainted Azazel: Features a shorter range but rapid-fire brimstone attack.
• Tainted Lazarus: Alternates between two versions after every room.

Each tainted character is a reimagined version of its base character, often with higher risks and rewards, making them perfect for players seeking variety and challenge.

Tips for Unlocking Tainted Characters

• Preparation is Key: Before attempting to unlock tainted characters, ensure you have a well-rounded build to handle the ascension and the challenges in Home.
• Explore Thoroughly: Carefully examine rooms for potential drops and use bombs to uncover hidden items or paths.
• Plan Trinket Placement: Strategically place trinkets in easily accessible rooms to streamline the process of creating Cracked Keys.
• Repeat the Process: The method remains consistent for all characters, so once you’ve unlocked one, you can follow the same steps to unlock others.

Why Unlock Tainted Characters?

Tainted characters provide a refreshing spin on the game by introducing unique mechanics and playstyles. They challenge players to adapt to new strategies and maximize their runs. Additionally, unlocking all tainted characters is a satisfying achievement that showcases your mastery of The Binding of Isaac.