Table of Contents

Unlocking All Completion Marks in The Binding of Isaac: A Comprehensive Guide

The Binding of Isaac, a roguelike dungeon crawler developed by Edmund McMillen and Florian Himsl, is renowned for its challenging gameplay and immense replayability. A key component of this replayability lies in the completion marks, which signify that you’ve successfully completed a run with a specific character against a specific boss. Collecting all completion marks Isaac offers can be a daunting task, but this comprehensive guide will provide you with the knowledge and strategies needed to achieve this feat. This guide aims to provide an objective and accurate overview of how to obtain all completion marks Isaac offers, ensuring a rewarding experience for both new and seasoned players.

Understanding Completion Marks

Before diving into the specifics, it’s crucial to understand what completion marks are and why they’re important. Completion marks are visual indicators displayed on the character selection screen, signifying that you’ve defeated a specific final boss with that character. Each character has the potential to earn multiple completion marks, and unlocking all completion marks Isaac requires a significant time investment and a solid understanding of the game’s mechanics.

These marks unlock new items, characters, and challenges, adding further depth to the game. They are essential for experiencing the full scope of The Binding of Isaac and achieving true completion. The primary completion marks are:

Mom’s Heart/It Lives: Defeating Mom’s Heart 10 times unlocks It Lives, a more challenging version of the boss.
Isaac: Defeating Isaac in the Cathedral.
Satan: Defeating Satan in Sheol.
The Lamb: Defeating The Lamb in the Dark Room (requires defeating It Lives 11 times to unlock the Negative).
Blue Baby (???): Defeating Blue Baby in the Chest (requires defeating It Lives 11 times to unlock the Polaroid).
Hush: Defeating Hush in the Blue Womb (requires defeating It Lives).
Mega Satan: Defeating Mega Satan (requires obtaining Key Pieces 1 & 2 from Angel Rooms or using Dad’s Key/Mr. ME!).
Delirium: Defeating Delirium (requires accessing the Void portal after defeating a final boss).
Mother: Defeating Mother in the Corpse (requires following a specific path detailed later).
The Beast: Defeating The Beast in the Home (requires following a specific path detailed later).

Character-Specific Strategies

Each character in The Binding of Isaac possesses unique starting items, stats, and abilities, influencing the optimal strategy for obtaining all completion marks Isaac offers. Here’s a breakdown of strategies for some key characters:

Isaac

Isaac is the default character and a good starting point for understanding the game. His defining feature is the D6, which allows him to reroll item pedestals. This makes him versatile and capable of adapting to different situations. For Isaac, focus on building a strong, consistent run. Use the D6 to reroll undesirable items and aim for powerful synergies.

Magdalene

Magdalene starts with the Yum Heart, a reusable healing item. This provides excellent sustain, making her ideal for beginners. Focus on defensive builds and prioritize items that increase health and healing. The key to mastering Magdalene for all completion marks Isaac involves patient and calculated plays.

Cain

Cain starts with a key and the Lucky Foot trinket, increasing his luck stat. This makes him more likely to find pills and chests. Utilize his luck to your advantage, aiming for items that synergize well with his starting stats. Knowing the pill effects is crucial for playing Cain effectively and obtaining all completion marks Isaac presents.

Judas

Judas starts with high damage but only one heart container. This makes him a high-risk, high-reward character. Play aggressively and prioritize damage upgrades. Avoid taking unnecessary risks, as one mistake can be fatal. Mastering Judas requires a strategic approach to maximize damage output and dodge enemy attacks, ensuring you can achieve all completion marks Isaac throws your way.

Azazel

Azazel starts with a powerful short-range Brimstone beam, making him incredibly strong in the early game. He’s one of the easiest characters to win with, especially for newer players. Use his powerful starting item to quickly clear rooms and build momentum. While his range is limited, his raw power helps secure all completion marks Isaac offers for him.

The Lost

The Lost is one of the most challenging characters. He starts with no health, can only take one hit, and starts with the Holy Mantle (one free hit per room). However, he also starts with spectral tears and flight. Success with The Lost hinges on avoiding damage and utilizing his unique abilities. The Lost requires patience, practice, and a deep understanding of enemy patterns to obtain all completion marks Isaac demands.

The Keeper

The Keeper is another difficult character, starting with only two coin hearts and the ability to hold up to two coins. He also takes increased damage. Prioritize defensive items and aim for items that generate coins. The Keeper is a test of resource management and skillful play, making the acquisition of all completion marks Isaac a significant achievement.

Tainted Characters

The Binding of Isaac: Repentance introduces tainted versions of each character, each with unique and often game-changing abilities. These characters offer new challenges and strategies for obtaining all completion marks Isaac. Some examples include:

Tainted Isaac: Can only hold 8 items, but can swap items out.
Tainted Magdalene: Hugs enemies for damage.
Tainted Cain: Crafts items using recipes.
Tainted Judas: Gains a damage multiplier after taking damage.

Route Planning: The Path to Victory

Planning your route through each run is crucial for maximizing your chances of success and obtaining all completion marks Isaac. Here’s a general guide:

First Few Floors: Focus on building a solid foundation. Look for items that increase your damage, health, or utility. Secret Rooms are often worth exploring early on.
Mid-Game: Decide which path you want to take. Do you want to go for the Cathedral (Isaac), Sheol (Satan), the Dark Room (The Lamb), or the Chest (Blue Baby)? Consider your character’s strengths and weaknesses when making this decision.
Hush: If you’re strong enough, consider fighting Hush. This requires defeating Mom in under 30 minutes. Hush drops powerful items and unlocks the Void portal.
Mega Satan: To fight Mega Satan, you need to obtain two Key Pieces from Angel Rooms or use Dad’s Key/Mr. ME!. Angel Rooms are more likely to appear if you avoid taking Devil Deals.
Mother/The Beast: These require specific paths. For Mother, bomb a skull marked with an X in the Downpour II or Dross II to obtain the Knife Piece 1. Then, bomb a fireplace in Mines II or Ashpit II to obtain Knife Piece 2. Combine the Knife Pieces in Mausoleum II or Gehenna II to open a door to Corpse. For The Beast, defeat Mother and then interact with the strange door in Depths II to start the ascent to Home.
Delirium: After defeating a final boss, a portal to the Void has a chance to appear. The chance increases if you fight Hush. Delirium is a challenging boss with unpredictable attacks.

Tips and Tricks for Success

Here are some general tips and tricks to help you obtain all completion marks Isaac:

Learn Enemy Patterns: Understanding enemy attack patterns is crucial for avoiding damage.
Prioritize Damage: Damage is often the most important stat. The faster you can kill enemies, the less likely you are to take damage.
Utilize Secret Rooms: Secret Rooms often contain valuable items and resources.
Understand Item Synergies: Some items synergize well with each other, creating powerful combinations.
Practice Makes Perfect: The more you play, the better you’ll become at the game.
Know the Pill Effects: Pills can have beneficial or detrimental effects. Knowing what each pill does can be a lifesaver.
Don’t Be Afraid to Restart: If you’re not happy with your starting items or the early floors, don’t be afraid to restart.
Angel Rooms vs. Devil Deals: Weigh the pros and cons of taking Devil Deals versus aiming for Angel Rooms. Devil Deals offer powerful items but cost health, while Angel Rooms offer potentially game-changing items without the health cost.

Advanced Strategies and Exploits

While mastering the basics is essential, some advanced strategies and exploits can significantly improve your chances of success in getting all completion marks Isaac. These strategies often involve manipulating game mechanics or exploiting item interactions.

Breaking the Game: Certain items, like Blank Card and Jera, can be used to duplicate items and resources, creating incredibly powerful runs.
Seed Manipulation: While generally discouraged, some players use seeds (specific codes that generate the same run) to practice specific strategies or overcome difficult challenges.
Devil Deal Optimization: Understanding the probabilities of Devil Deal appearances and the value of different Devil Deal items is crucial for maximizing their effectiveness.

Conclusion: The Path to Completion

Obtaining all completion marks Isaac in The Binding of Isaac is a challenging but rewarding endeavor. It requires a deep understanding of the game’s mechanics, strategic route planning, and skillful execution. By following the strategies and tips outlined in this guide, you’ll be well on your way to unlocking the full potential of each character and experiencing everything that The Binding of Isaac has to offer. Remember to stay patient, adapt to different situations, and never give up. The journey to completion is long, but the sense of accomplishment is well worth the effort. The key is to learn from each run, experiment with different strategies, and most importantly, have fun. Good luck, and may your runs be filled with powerful items and successful boss battles. This guide should provide a solid foundation for tackling the challenges and ultimately achieving all completion marks Isaac offers. [See also: The Binding of Isaac Item Synergies] [See also: Best Characters in The Binding of Isaac] [See also: How to Unlock All Characters in The Binding of Isaac]