The Binding of Isaac: Rebirth Item Pools Guide
Learn every item pool in Isaac Rebirth — treasure, devil, angel, boss, shop, secret, curse, and ultra secret pools. Understand pool rules, dilution, and deal mechanics.
Item pools are the hidden categories that determine where each item can spawn during a run. When you enter a treasure room, the game rolls from the treasure pool. When you open a devil deal, it rolls from the devil pool weighted by your current items and unlocks. Mastering pool mechanics is essential for predicting what items you might find and planning your unlock strategy to avoid diluting powerful early pools with weak unlocked items.
Core Item Pools
| Pool | Source | Notes |
|---|---|---|
| Treasure | Treasure rooms (one per floor) | Largest pool. Quality weighted in Repentance. |
| Devil | Devil room deals | Costs red heart containers. Taking a deal blocks angel rooms unless Goat Head. |
| Angel | Angel room deals | Free items. Requires not taking devil deals on current floor. |
| Boss | Boss drop after floor boss | One item per floor boss. Often stat upgrades or familiars. |
| Shop | Shop purchases | Costs coins. Restock machines refresh inventory. |
| Secret | Secret rooms | Bomb or key required to enter. Contains pickups and sometimes items. |
| Ultra Secret | Ultra secret rooms (Repentance) | Rare rooms with high-quality items. Requires specific entry methods. |
| Curse | Curse room items | Picking up cursed items damages you but can be powerful. |
| Greed | Greed mode shop | Separate pool for Greed and Greedier mode waves. |
Devil and Angel Room Rules
Devil rooms appear when your devil deal chance exceeds the threshold, influenced by taking damage, killing bosses quickly, and holding certain items like Black Candle. Angel rooms replace devil rooms if you have not taken a devil deal on the current floor and meet angel room conditions. Goat Head forces devil and angel rooms to appear and allows both on the same floor. Duality merges devil and angel pools into combined deals. Eucharist guarantees angel rooms. Understanding these rules helps you plan whether to take damage for devil deals or preserve angel room access for Sacred Heart and Holy Mantle.
Pool Dilution and Unlock Impact
Every item you unlock adds entries to one or more pools. Unlocking 50 weak items dilutes your treasure pool, making it harder to find quality 4 items naturally. This is why experienced players recommend delaying certain unlocks until later in your Dead God journey. The optimal unlock order guide explains which secrets to prioritize and which to save for last. Items unlocked through completion marks are generally strong and worth unlocking early.
Special Pool Interactions
- Sacred Orb — Rerolls low-quality boss and shop items into higher quality alternatives from the same pool.
- Tainted Lost — Only sees quality 4 items in shops and devil deals, fundamentally changing pool value.
- NO! — Prevents quality 0 and 1 active items from appearing in shops and devil deals.
- Chaos — Pulls items from random pools, enabling devil pool items in treasure rooms.
- Red Key — Creates red room variants that can contain items from special pools not normally accessible on Home.
For a complete list of which items belong to which pools and their quality ratings, cross-reference our all items guide and quality tier list. Greed mode uses its own separate pool documented in the Greed mode guide.
Frequently Asked Questions
Can angel and devil rooms both appear on the same floor?
Normally no — taking a devil deal prevents angel rooms on that floor. Goat Head and Duality are exceptions that allow both or merge their pools.
What is pool dilution?
As you unlock more items, they enter global pools and reduce the chance of finding any specific item. Unlocking many weak items makes strong items statistically rarer.
How do I increase devil deal chance?
Take damage on the floor, kill the boss quickly, hold items like Black Candle, and avoid certain pills. Devil deal chance is displayed implicitly through room generation.
What is an ultra secret room?
Added in Repentance, ultra secret rooms contain high-quality items and require specific conditions to access, such as using certain cards or entering from particular room layouts.
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