Challenges

Challenges are unique runs in the game. Challenges typically start the player off with one or more specific items which make normal play more difficult. You will not find Treasure Rooms (with the exception of a select few challenges). Completing one of the thirty five challenges unlocks new content for the game, such as Runes.

General Strategy

Most challenges are geared to make a run difficult in some form. Sometimes, these challenges are easy, like Computer Savvy. Other times, they can be vicious, like Solar System. Each challenge has a certain strategy that can make the run easier. However, there are a few strategies that can apply to all challenges.

• You can play in co-op for every challenge, making it easier for the ones where you cannot fire tears - especially for Cat Got Your Tongue, since it will spawn flies.
• Because of the lack of Treasure Rooms, Devil Rooms become much more valuable. Some challenges can be made much easier by making just one deal.
• You can also be more liberal with your use of keys for the same reason. Trinkets and Items that generate more coins, along with upgraded shops, can help reduce the difficulty in many challenge runs.
• The BibleUpon activation, Isaac gains flight, allowing him to pass over all obstacles in the current room. Instantly kills Mom, Mom's Heart, and It Lives when activated, but will kill Isaac when activated while fighting Satan. can make the end of some runs extremely easy. Because of how some challenges operate, the run may only require defeating Mom or Mom's Heart / It Lives. Since The BibleUpon activation, Isaac gains flight, allowing him to pass over all obstacles in the current room. Instantly kills Mom, Mom's Heart, and It Lives when activated, but will kill Isaac when activated while fighting Satan. is a one-hit kill against these, getting it when you have the chance is usually a good investment for these runs.
  • Pandora's BoxUpon use, spawns certain pickups or items depending on the floor it is used on. Single-use. will spawn The BibleUpon activation, Isaac gains flight, allowing him to pass over all obstacles in the current room. Instantly kills Mom, Mom's Heart, and It Lives when activated, but will kill Isaac when activated while fighting Satan. if used in Womb II, Utero II, or Scarred Womb II, which may then be used against Mom's Heart / It Lives.
• Curse Rooms gain value since they can spawn items. You may wish to restart on the first floor until your Curse Room spawns an item worth 1 heart of damage.
• Dice Rooms and the D4Rerolls all of Isaac's items. are very useful, as in some cases you can reroll your entire build and remove (or add) difficulty.
  • Dice rooms do not re-roll starter challenge items or remove Blindfolded.
  • Butter!Using an active item will drop it onto a pedestal on the ground. Taking damage may result in dropping a passive item. can remove starter items.
• In Blindfolded challenges, familiars can make the run easier, as they are your only source of conventional damage. Powerful familiars like Daddy LonglegsDaddy Long Legs' shadow follows Isaac and stomps on enemies., Lil BrimstoneA Familiar that shoots a thin Brimstone beam. Must charge like Brimstone before shooting., and IncubusA demonic familiar that follows Isaac and shoots tears identical to Isaac's in terms of damage, range, fire rate, and effects. are very good items to pick up. Some of the strongest familiars need to be unlocked first, so it may be wise to take the time to unlock them beforehand.
  • The BoomerangThrows a short-range boomerang which does a bit of damage and has a high chance to stun the enemy for 2 seconds. Can also be used to grab pickups., The CandleThrows out a blue flame that can pass over gaps (but not through rocks). The flame damages anything in its path., and Red CandleThrows a persistent flame that deals high damage and diminishes as it damages enemies or blocks shots. are also useful for blindfolded challenges, since they deal damage and recharge based on a timer.
    • In Blindfolded challenges, if possible finding and using the ClickerTransforms Isaac into another random character., change yourself into the character Lilith, will make these challenges incredibly easy with access to tears through her IncubusA demonic familiar that follows Isaac and shoots tears identical to Isaac's in terms of damage, range, fire rate, and effects. you gain.

• In challenges that remove Treasure Rooms, ChaosChaos causes items to be chosen from random item pools. When picked up, drops between 1-6 random pickups on the floor. has more potential to be useful by potentially making Treasure Room (among other rare items) items purchasable from the shop. On the downside, it may replace the Devil/Angel Room items with something less valuable.
• Defeating a boss beyond the specified end of the challenge (e.g. defeating Mom's Heart when the goal is to defeat Mom) will still cause them to drop the trophy.
  • This means a legitimate tactic for some of the longer challenges (e.g. XXXXXXXXL) is to use the Sacrifice Room until it teleports you to the Dark Room, then going through and defeating The Lamb, completing the challenge regardless of what floor you were teleported from.

Notes

• New content, other than the Challenge Reward, cannot be unlocked. Likewise, you will not find a Donation Machine anywhere.
• The Challenge reward will not be unlocked unless you pick up the trophy, meaning that if a Devil Room or Angel Room appears and allows you to go to Sheol or the Cathedral, you will be forfeiting the unlock if you fail to complete the floor.
• Any challenge featuring Isaac will not start with The D6Allows Isaac to re-roll collectible items in the current room into other items, depending on the current room's Item Pool..

Challenge list

Challenges

Rebirth
1.	Pitch Black	2.	High Brow	3.	Head Trauma	4.	Darkness Falls	5.	The Tank	6.	Solar System	7.	Suicide King	8.	Cat Got Your Tongue
9.	Demo Man	10.	Cursed!	11.	Glass Cannon	12.	When Life Gives You Lemons	13.	Beans!	14.	It's in the Cards	15.	Slow Roll	16.	Computer Savvy
17.	Waka Waka	18.	The Host	19.	The Family Man	20.	Purist
Afterbirth
21.	XXXXXXXXL	22.	SPEED!	23.	Blue Bomber	24.	PAY TO PLAY	25.	Have a Heart	26.	I RULE!	27.	BRAINS!	28.	PRIDE DAY!
29.	Onan's Streak	30.	The Guardian
Afterbirth †
31.	Backasswards	32.	Aprils Fool	33.	Pokey Mans	34.	Ultra Hard	35.	Pong