After watching Northernlion struggling with random number generators to avoid ruining his Binding Of Isaac streak by picking up The Lost, I decided to write this randomizer for Isaac.
It works around the concept of "deck of cards", where each card represents an Isaac character and where the same card can be put up to 5 times in the deck (or be entirely discarded). The randomizer includes two different modes:
In the "top card" mode, the deck is shuffled once and the card on top of the stack is picked, and removed from the deck. When the deck is completely depleted, it's shuffled again. This system ensures that you'll get to play all the characters you want within a certain number of plays.
In the "any card" mode, the cards are picked at random from the deck and are not discarded, which makes it impossible for you to guess which card is "due".