The Binding of Isaac: Rebirth Challenges Guide

Challenges are curated runs with preset characters, starting items, and modified rules that test specific skills. Unlike normal runs, challenges disable most treasure rooms and lock your build to predetermined items plus whatever you find in shops, devil deals, and boss drops. There are 45 official challenges across Rebirth, Afterbirth, Afterbirth+, and Repentance — each unlocking a card, rune, item, or achievement when completed. Challenges cannot unlock other secrets during the run.

Challenge Structure and Rules

Each challenge specifies a character, starting items, optional curses, disabled room types, and a win condition (usually defeating a specific boss). Most challenges disable treasure rooms entirely, forcing you to work with your starting kit. Some challenges modify fundamental mechanics — Backasswards starts at the Dark Room and ascends backward, Ultra Hard applies nearly every curse with no health drops, and DELETE THIS randomizes every floor theme. Completing a challenge grants its unlock reward immediately and permanently adds that content to your save file.

Challenge Categories by DLC

Hardest Challenges and Tips

• Ultra Hard (#34) — No health drops, all curses, all champions, goal is Mega Satan. Requires near-perfect play and RNG tolerance.
• Purist (#20) — No treasure, devil, or angel rooms. Only starting items and boss drops. Tests fundamental dodging skill.
• Backasswards (#31) — Reverse floor order starting at Dark Room. Lose oldest item and a heart container each floor.
• DELETE THIS (#45) — Completely randomized floors that can softlock. Repentance's meme challenge for masochists.
• Onan's Streak (#29) — Ranges-only tears. Any non-range tear upgrade ruins your run instantly.

Optimal Challenge Order

Prioritize challenges with high-value unlocks early. Computer Savvy (#16) is easy and unlocks useful content. The Tank (#5) and Solar System (#6) are straightforward for experienced players. Save Ultra Hard, Backasswards, and DELETE THIS for late progression when your game knowledge is deep. Repentance challenges 36–45 unlock powerful items like Spirit Sword and Marbles that enter the global pool — completing them early slightly dilutes pools but the items themselves are worth having.

All 45 challenges must be completed for Dead God and the 1001% achievement. Challenge runs do not allow other secret unlocks — you cannot get completion marks or character unlocks during a challenge. Use our challenge completion guide with video walkthrough for priority ordering and individual strategies. Cross-reference the Dead God guide to see where challenges fit in your overall completion timeline.