Chest Loot System
Chests scattered through the mine each have a loot level (1–12) that controls passive multipliers, gem drops, and equipment scroll pools.
How it works: One item is chosen at random from the full loot pool.
The pool always contains 3 passive upgrade slots. At levels 1–4, it also contains
1 gem slot and 1 equipment scroll slot (pool size = 5, each item has 20% chance).
At levels 5–12, only passives remain (pool size = 3, each has 33% chance).
Passive multiplier formula:
Levels 1–4: multiplier = loot_level (linear).
Levels 5–12: multiplier = loot_level² (quadratic).
A level-12 chest gives ×144 — a passive with +5% base grants +720% per pick.
Loot Level Overview
| Level | Passive Mult. | Gem Drop | Gem Value | Pool Size | Passive Odds | Gem Odds | Scroll Odds |
|---|---|---|---|---|---|---|---|
| 1 | ×1 |  Amethyst (1-2) | $70 | 5 | 60% | 20% | 20% |
| 2 | ×2 |  Ruby (1-2) | $500 | 5 | 60% | 20% | 20% |
| 3 | ×3 |  Diamond (1-2) | $4,000 | 5 | 60% | 20% | 20% |
| 4 | ×4 |  Pink Diamond (1-2) | $7,500 | 5 | 60% | 20% | 20% |
| 5 | ×25 | — | — | 3 | 100% | — | — |
| 6 | ×36 | — | — | 3 | 100% | — | — |
| 7 | ×49 | — | — | 3 | 100% | — | — |
| 8 | ×64 | — | — | 3 | 100% | — | — |
| 9 | ×81 | — | — | 3 | 100% | — | — |
| 10 | ×100 | — | — | 3 | 100% | — | — |
| 11 | ×121 | — | — | 3 | 100% | — | — |
| 12 | ×144 | — | — | 3 | 100% | — | — |
Equipment Scroll Pools (Levels 1–4)
When an equipment scroll is won, a random weapon from the level's pool is granted
for 10 seconds. Scroll stats are marked PLACEHOLDER — see
resources/Items/Equipment/*.tres for actual values.
Level 1 — Amethyst tier
| Item ID | Tier | Duration | Stats |
|---|---|---|---|
 minigun_08_gold | gold | 10s | Extract from .tres file |
 rifle_08_gold | gold | 10s | Extract from .tres file |
 shotgun_08_gold | gold | 10s | Extract from .tres file |
 staff_08_gold | gold | 10s | Extract from .tres file |
 flamethrower_3 | tier3 | 10s | Extract from .tres file |
 electric_pickaxe_08_gold | gold | 10s | Extract from .tres file |
 poison_staff_1 | tier1 | 10s | Extract from .tres file |
Level 2 — Ruby tier
| Item ID | Tier | Duration | Stats |
|---|---|---|---|
 minigun_09_ruby | ruby | 10s | Extract from .tres file |
 rifle_09_ruby | ruby | 10s | Extract from .tres file |
 shotgun_09_ruby | ruby | 10s | Extract from .tres file |
 staff_09_ruby | ruby | 10s | Extract from .tres file |
flamethrower_3 | tier3 | 10s | Extract from .tres file |
 electric_pickaxe_09_ruby | ruby | 10s | Extract from .tres file |
 poison_staff_2 | tier2 | 10s | Extract from .tres file |
Level 3 — Diamond tier
| Item ID | Tier | Duration | Stats |
|---|---|---|---|
 minigun_10_diamond | diamond | 10s | Extract from .tres file |
 rifle_10_diamond | diamond | 10s | Extract from .tres file |
 shotgun_10_diamond | diamond | 10s | Extract from .tres file |
 staff_10_diamond | diamond | 10s | Extract from .tres file |
 flamethrower_4 | tier4 | 10s | Extract from .tres file |
 electric_pickaxe_10_diamond | diamond | 10s | Extract from .tres file |
 poison_staff_3 | tier3 | 10s | Extract from .tres file |
Level 4 — Pink Diamond tier
| Item ID | Tier | Duration | Stats |
|---|---|---|---|
 minigun_11_pinkdiamond | pinkdiamond | 10s | Extract from .tres file |
 rifle_11_pinkdiamond | pinkdiamond | 10s | Extract from .tres file |
 staff_11_pinkdiamond | pinkdiamond | 10s | Extract from .tres file |
flamethrower_4 | tier4 | 10s | Extract from .tres file |
 electric_pickaxe_11_pinkdiamond | pinkdiamond | 10s | Extract from .tres file |
Passive Selection Screen
When a chest gives a Passive Upgrade, the player sees 3 options.
The options are biased toward passives that match equipment currently in the player's inventory
(via PASSIVE_MAP in choose_passive.gd). Each option shows:
"Increase [Stat Name] +X%" where X = multiplier × base_per_pick × 100.
Passive multipliers grow sharply at high levels. A level-8 chest (×64 multiplier) gives
a +320% boost to a 5%-base passive per pick — the same as 64 picks from a level-1 chest.