Spire Codex is now on Overwolf. Get the in-game overlay with live card lookups and one-click run uploads. Learn more →Spire Codex is now on Overwolf. Get the in-game overlay with live card lookups and one-click run uploads. Learn more →What happens when you enter a "?" room, including the adaptive odds for events, fights, shops, and treasure, and the between-acts reset.
| Outcome | Base Chance | Adaptive |
|---|---|---|
| Event | Whatever is left | 100% minus the current fight/shop/treasure odds; shrinks as those build from misses, jumps back when one of them hits and resets |
| Monster fight | 10% | +10% each miss |
| Shop | 3% | +3% each miss |
| Treasure | 2% | +2% each miss |
| Elite | Never (odds are negative by default) | Only rollable via modifiers like Deadly Events; negative odds never increase from misses |
The game makes one random roll from 0 to 1 and walks the non-event outcomes in a fixed order (monster, elite, treasure, shop), adding each one's current odds to a running threshold. The first outcome whose cumulative threshold covers the roll wins; if the roll clears them all, the room is an event. After the roll, the outcome that hit resets to its base odds, and every other eligible outcome increases by its own base amount.
This is the detail most community explanations miss: all adaptive odds reset to their base values at every act transition (ResetToBase() in the game's UnknownMapPointOdds, "Called between acts"). Pity never carries across an act boundary.
That resolves the streaks that look impossible under a run-long model. A run can see seven straight events, or ten "?" rooms without a single fight, because the fight odds never accumulate past an act's worth of misses. With roughly 4-6 unknown rooms per act, monster odds top out around 50-60% before the reset wipes them, and nothing is ever guaranteed.