Playing with ??? is a challenge, but his drawback also comes with upsides. His main gimmick relies on exploiting health based items or rooms.

StrategyEdit

GeneralEdit

• The chance of Soul Heart drops is slightly increased. (From 30% to 50%)
• The Devil Room/Angel Room has an increased chance of spawning. The Devil Room/Angel Room has a greater chance of spawning if you do not take red heart damage on a floor and beat a boss fight without taking red heart damage. ??? can't take red heart damage so he always gets these increased chances.
  • The Devil Room will always offer items at the price of three Soul Hearts. However, certain items provide the player with Soul Hearts when picked up (The Pact with two, The Mark with one), making them more viable overall.
  • If you don't purchase anything in the Devil Room, the chances for an Angel Room to spawn are high. Angel Rooms offer great items for free (especially the Mitre and the Relic), and they're not detrimental to ???'s health.
• Since ??? only has Soul Hearts and cannot acquire Heart Containers, the usually risky condition of having only a half-heart or no heart containers left is always present.
  • Boss Challenge Rooms are always opened.
  • Challenge Rooms are always opened.
  • The Whore of Babylon item will always be active.
  • The Polaroid will always provide the damage shield upon taking damage.
  • Trinkets or other items that activate when the player is down to half a heart are active every time the player takes damage (Umbilical Cord, etc). 
  • Scapular is an exception, and will only activate when ??? reaches 0 soul hearts.  When this happens, ??? receives 1 soul heart.  This effect can only occur once per room.
• While Eternal Hearts can only turn into Soul Hearts, it's basically impossible to lose them by taking damage (since ??? will die from having no Soul Hearts left at first).
  • Keep in mind that using the Blood Donation Machine, IV Bag or a Devil Beggar will still use up Eternal Hearts first.
• Effects that temporarily grant the character an additional Heart Container will give ??? a permanent Soul Heart instead.
  • This makes the tarot card XI Strength particularly useful.
  • The trinket Liberty Cap gives a random mushroom effect whenever the player enters another room. One of them provides a health up, but ??? can only gain one Soul Heart per playthrough in this fashion.

Tips and tricksEdit

• Buy Soul Hearts in Shops.
• The Poop recharges with every room. Always use it, as even its minimal chance of providing pennies can make the difference.
  • Always pop the poop pile created by it before leaving the room, since it will despawn otherwise.
  • Consider using it as an obstacle for enemies or their projectiles.
• X Marks the Spot rocks become even more useful because of the importance of Soul Hearts. Consider using your bombs on those instead of attempting to find the Secret Rooms.
  • If the rocks are adjacent to a wall, place your bomb in between so you keep the possibility of opening up a Secret Room.
• Having The Wafer allows you to make deals with the Devil for only a half-heart. Also works with the Wrath of the Lamb expansion.
• Curse Rooms have a high risk, high reward. You end up losing one Soul Heart (without assuming ??? has flight or the ability to teleport back out), but have the chance of getting two or even four Soul Hearts back, acquiring a Devil Room/Angel Room item, pills, and might also discover an adjacent (Super) Secret Room.
  • You can check them out on the first floor and still reset the playthrough if it didn't work out nicely.

ItemsEdit

Best Items:

• Book of Revelations
• The D6 ( for rerolling bad items )
• The Mark
• The Polaroid
• Bucket Of Lard
• The Nail
• The Pact
• The Relic
• Mitre
• Crystal Ball
• Rosary
• Squeezy
• Mom's Pearl
• V The Hierophant, VIII Justice, and XI Strength (??? keeps the Soul Heart that it gives, on another character, it would add another Heart Container for that room)
• Balls of Steel and Health Up pills
• Book of Shadows, The Gamekid, My Little Unicorn, and VII The Chariot (Especially good because of a bug that allows an invincible ??? with at least 3 Soul Hearts to steal from a Devil Room)
• Celtic Cross (Keep in mind that it is redundant with the Polaroid.)
• Scapular (especially when combined with the Cursed Skull trinket, as it makes ??? invincible, but the player will be forced to leave the room uncompleted upon taking one hit)

Good Items:

• D20 (can be used to reroll heart pickups into Soul Hearts)
• <3 (will only recover Soul Hearts when ??? is below three Soul Hearts)
• The Tick (still takes 15% health off of bosses, but doesn't heal ??? and can't be removed as always unless you have Mom's Purse)

Bad Items:

• Kamikaze!
• Razor Blade
• IV Bag (you can still use an IV Bag with invincibility granting items, same goes for Blood Donation Machines and Devil Beggars)
• Charm of the Vampire
• Little C.H.A.D.
• Yum Heart
• Child's Heart
• Judas's Tongue
• Umbilical Cord
• Guppy's Paw (it is still advisable to pick it up in a Curse Room because of a potential Guppy transformation)
• Bloody Penny
• Isaac's Fork
• VI The Lovers
• 2 of Hearts

Playable Characters
Isaac	Magdalene	Cain	Judas	Eve	???	Samson
Strategy	Strategy	Strategy	Strategy	Strategy	Strategy	Strategy