Special items are items in the game that are considered stronger than normal by the developers.
If Isaac sees a Special Item, subsequent Special Items have a chance of being re-rolled rather than being presented to Isaac, decreasing the likelihood of Isaac obtaining multiple Special Items.
The current list of special items is as follows :
- D100*
- The D6*
- Dr. Fetus*
- Epic Fetus*
- Lil' Brimstone
- The Ludovico Technique
- Mutant Spider
- Polyphemus
- Pyromaniac
- Soy Milk
- Mom's Knife* (Devil & Treasure Item)
- Brimstone (Devil Item)
- Stop Watch* (Shop Item)
- Sacred Heart (Angel Item)
- Godhead* (Angel Item)
- * - unlockable items
Special Item Generation
When you enter a room with an item in it, items are selected out of certain pools depending upon the room you are currently in.
Special items have a chance of being re-rolled rather than being presented to Isaac depending on how many special items Isaac already saw.
This percentage chance is 100% * (1 - 0.5 ^ (number of special items Isaac saw)).
This means, at the start, the game has a 0% chance of re-rolling the special item it generated at first, then the chance increases to 50% at the start, and subsequent special item pickups increase the chance to 75%, 88%, 94%, etc.
Notes
- Isaac's D6 doesn't count as a "seen" special item, as it is directly given to him when the run starts.
- Special items given by D4, D100, or 1/6 Dice Rooms are items generated by the game, and thus count as "seen" special items.
- Since seeing a special item is enough, you have no way to prevent the reroll chance from increasing, like you could do in the original by not taking special items.
- Even if a special item will act like a normal item once it has been seen, this may not be a good idea to pick them all, as most of them are heavy tear modifiers and can override other tear items that Isaac picked without increasing its dps.
- Since the reroll chance rapidly increases to a high percentage, seeing 3-4 special items can be enough to make some special items that aren't in Treasure Room Pool (Godhead, Sacred Heart, Brimstone,..) require hundreds of D6 rolls before appearing.
- However, these special items will always appear after a certain number of rerolls, even if the Treasure Room Pool was emptied and Breakfast starts to appear. In these situations, infinite D6 uses and patience are required.