- Upon use of an activated item, activates the effect of another random activated item.
- The random effect is any activated item with charge time of 1 or 2 rooms. View the page on activated items for a complete list.
- Timed recharge and infinite use items trigger the effect once per room. Re-entering the room will allow Expansion Pack to trigger again.
- One time use, timed recharge and infinite use item effects are not available.
- D Infinity, Dead Sea Scrolls, and Metronome all qualify for Expansion Pack as their (base) charge time is 2 rooms. This may result in activations of items not normally selectable by Expansion Pack.
- If an item like Bob's Rotten Head or Shoop Da Whoop! is selected, firing it will be counted as another item use and active Expansion Pack a second time.
|Active Item Modifiers|
|Tainted Bethany Unlocks|
|Isaac (Boss) Unlocks|
|The Lamb Unlocks|
|??? (Boss) Unlocks|
|The Binding of Isaac: Rebirth|
|Achievements||Attributes||Bosses||Cards and Runes||Challenges||Chapters|