Chests while fishing
Patch 1.7.3: Mirror Lake — when keys are spare
What it is
Chests while fishing (thanks, Holyjester). When fishing actively, a catch can also bring a chest whose keys you have spare. The chance rises with depth.
The chance by depth
Per active catch: 0.3% near the shore, 0.15 percentage points more per 100 m of depth, at most 3% (from 1,800 m).
| Depth | Chance per catch |
|---|---|
| near the shore | 0.3% |
| 500 m | 1.05% |
| 1,000 m | 1.8% |
| 1,500 m | 2.55% |
| from 1,800 m | 3% |
The knack “Treasure Sense” applies here too: Per level 15% more chests and keys in the water, and more often something in a fish's belly.
Which chest hangs on the hook
Only chests that lie at this depth count, and only if you own more of their keys than chests (bag, mailbox and bank are counted). If there are several, the kind with the largest surplus comes.
| Chest | Key | Depth |
|---|---|---|
 Reed Crate |  Rust Key | 5–90 m |
 Drowned Casket |  Brass Key | 80–230 m |
 Floor Shrine |  Ember Key | 200–450 m |
 Rift Reliquary |  Mirror Key | from 420 m |
 Ember-Veined Chest |  Vein Key | 650–1,150 m |
 Iron Deep Chest |  Iron Deep Key | 1,000–1,800 m |
 The Floor Casket |  Floor Key | from 1,500 m |
When it does not apply
- only when fishing actively, not on the set line
- only if keys of a chest at this depth are spare — otherwise the catch stays as it was
At the Mirror Lake, the box “Chests and keys” (tab “Treasures”) shows the chance near the shore and at 1,000 m depth.
