The Chest and The Dark Room...

[D.A.R.K.]

First, sorry for bad english, I`m from Brazil.
There`s anyway I can have a 100% chance to spawn any of that room after defeat Isaac or Satan? I already have 100% to go to Sheol or Cathedral after defeat It Lives, but I defeat Satan some times [Isaac just once] and the passage to The Dark Room just don`t open to me.

[AlarminglySvelte]

If you defeat Isaac five times you unlock an item that opens the way to the Chest, and if you defeat Satan five times you unlock an item that opens the way to the Dark Room. They're both opposites, so you can only carry one at a time. Hope that answers your question (without spoiling too much)

[ZetaStriker]

Four kills on Issac/Satan unlocks the Polaroid/Negative, both of which spawn after killing Mom, I believe. Holding the Polaroid lets you get into the Chest after killing Isaac, and holding the Negative lets you go to the Dark Room after killing Satan.

EDIT: Is it five times? I thought it was a four-piece puzzle that shows up on the save screen, but I could be wrong.

[Sloppy Seconds]

The polaroid unlocks the chest after the cathedral, 100% of the time.

The negative unlocks the dark room after sheol, 100% of the time.

You can skip both of these requirements by finding a trap door or creating one with the shovel.

Originally posted by ZetaStriker:

EDIT: Is it five times? I thought it was a four-piece puzzle that shows up on the save screen, but I could be wrong.

Yes, it's 5 times.

[AlarminglySvelte]

Originally posted by ZetaStriker:

Four kills on Issac/Satan unlocks the Polaroid/Negative, both of which spawn after killing Mom, I believe. Holding the Polaroid lets you get into the Chest after killing Isaac, and holding the Negative lets you go to the Dark Room after killing Satan.

EDIT: Is it five times? I thought it was a four-piece puzzle that shows up on the save screen, but I could be wrong.

I had to beat Satan five times, but I didn't keep track for Isaac. It's a couple of times, anyway

[D.A.R.K.]

Thanks guys, just one more question, Polaroid or Negative has 100% chance to spawn in the run or I have to be lucky?

[ZetaStriker]

100% chance after unlock, but you can only pick one of the two so make sure you go through the right door after Mom's Heart.

[Sloppy Seconds]

Originally posted by D.A.R.K:

Thanks guys, just one more question, Polaroid or Negative has 100% chance to spawn in the run or I have to be lucky?

Double item drop after mom fight, implying you can only pick up one or the other.

[D.A.R.K.]

Really greatful, thanks.