Chests and loot

3 chest tiers · where gear, materials and gems drop

Beta 0.7.2

Kills give gold and XP; gear, materials and gems drop from chests. The rarer the chest, the more often it holds an item and the better its rarity rolls.

The three chests

Common chest

Colour: Brown
Held: 6 → 16
Auto-open: 15 min → 10 min
Chest luck: +0

From kills

Stage-boss chest

Colour: Blue
Held: 4 → 8
Auto-open: 1 h → 30 min
Chest luck: +0.3

From stage bosses

Act-boss chest

Colour: Red
Held: 2 → 4
Auto-open: 1 min → 10 s
Chest luck: +1

From act bosses

What is inside

A chest's contents are rolled when you open it, from a seed fixed when it dropped. One roll picks the kind:

Result	Common chest	Stage-boss and act-boss chests
One item	50%	90%
One ore or essence	39.5%	0%
Dispel Scroll	0.5%	0%
One gem	10%	10%

Your first common chest always holds an item. From stage 6 of each act, a common or stage-boss chest can turn into a riftstone instead (see Rift & Colossus).

How each result rolls

Item slot	Common chests roll only the 8 non-jewellery slots; stage-boss chests give jewellery (necklace, earrings, bracelet, ring) 10% of the time; act-boss chests can roll any of the 12 slots.
Class and armour	Weapons and offhands roll for the classes of your heroes, party and reserve, and armour for their armour weights, favouring the party 80% of the time. With the "Loot only for the party" setting on, they roll for the party only.
Material	53.5% ore, 46.5% essence, always 1 unit. A "rare proc" bumps the tier by one, with a chance of 4% × (1 + x), at most 50% (x as in the rarity formula). From tier 2 up there is a 25% chance to drop a random lower tier instead. See Materials & potions.
Gem	In a biome with an element, half of all gems are that element's gem; otherwise any of the 24 gems, evenly.
Before unlocks	Until the workbench's socket station is unlocked, gem results become materials; until enchanting is unlocked, Dispel Scrolls do too.

Rarity and luck

An item's rarity is a weighted roll. Better chests scale the top rarities less and add flat luck, and your party's Luck pushes the odds further up, with diminishing returns. Pick a party Luck to see the odds per item:

Chest	Common	Uncommon	Rare	Heroic	Mythic	Legendary	Eternal
Common chest	68.28%	20.48%	8.19%	2.87%	0.143%	0.0344%	0.0017%
Stage-boss chest	61.07%	22.55%	11.1%	4.78%	0.385%	0.114%	0.0028%
Act-boss chest	52.73%	23.73%	14.24%	7.48%	1.33%	0.481%	0.0061%

With no Luck, about 1 common-chest item in 697 is Mythic and 1 in 58,120 is Eternal.

How the roll works

x = party Luck ÷ 10,000 + chest luck (common 0, stage-boss 0.3, act-boss 1)
luck factor = 1 + x ÷ (1 + x)
weight = rarity weight × luck factor^step (step 0 for Common … 5 for Legendary, 1.6 for Eternal)

Base weights: Common 1,000, Uncommon 300, Rare 120, Heroic 42, Mythic 5, Legendary 1.2, Eternal 0.06. Mythic and above are multiplied by 0.42 in common chests (and the forge) and 0.55 in stage-boss chests.

Where Luck comes from

Rune of the Gambler+1%

Rune of Destiny+2%

Magpie pet+0.5%

Fortune runeword+1% to +12%

Topaz gems

Luck affixes on gear

Luck is counted in hundredths of a percent (100 = 1%) and summed over the party's heroes.

Item level

Items drop in level steps: 1, 10, 20 … 100. An item takes the highest step at or below the level the chest rolls:

Common chest	The step of the stage's recommended level, but always the next step one or two levels before it. The game's 1-in-3 and 2-in-3 chances are tested against the roll that dropped the chest, and with the shipped settings every brown chest comes from the kill guarantee, which counts as a roll of 0. Item level
Stage-boss chest	In practice the stage's recommended level + 2, capped by your best hero's level.
Act-boss chest	The act boss's recommended level + 2. The Veil act 6 boss (recommended level 20) gives level-20 items; the Abyss act 10 boss gives level 100.
Gem tier	1 + (raw chest level ÷ 20, rounded down), from 1 to 5.
Material tier	Tier 1 up to level 10, tier 2 up to 30, tier 3 up to 50, tier 4 up to 70 and tier 5 above.

Stage levels for every stage are on Maps & stages.

How chests are earned

Common chests

A kill has no chance to drop a common chest. The game counts kills since your last one and hands one over when the count reaches the larger of two numbers, a kill guarantee and a time floor turned into kills at your current kill speed:

kills per chest = max(guarantee, ceil(time × kills per second))
guarantee = round(90 × (1 + 0.0018 × max(0, level − 20)²)) ÷ (1 + drop find)
time = max(floor, floor × (1 + bonus) ÷ (1 + drop find))

Stage level	Kill guarantee	Time	With +50% drops	With +80% drops	Most per hour
1	90	216 s	180 s	180 s	16.7
10	90	405 s	300 s	300 s	8.9
20	90	405 s	300 s	300 s	8.9
30	106	607.5 s	450 s	450 s	5.9
40	155	607.5 s	450 s	450 s	5.9
50	236	652.5 s	450 s	450 s	5.5
60	349	652.5 s	450 s	450 s	5.5
70	495	652.5 s	450 s	450 s	5.5
75	580	1,080 s	720 s	600 s	3.3
80	673	1,080 s	720 s	600 s	3.3
90	884	1,260 s	840 s	700 s	2.9
100	1,127	1,260 s	840 s	700 s	2.9

At normal farming speed the time floor wins, so you get one common chest per stretch of fighting time. "Most per hour" is with no drop bonus, once you kill fast enough for the time floor to decide (at stage level 40, above 0.26 kills a second).

Drop bonuses and a worked example

Item drop bonuses (Codex, pets) cut both numbers: they divide the kill guarantee and shorten the time down to its floor. The Codex's +75% item drops plus the Magpie's +5% reach the floor everywhere below level 90.

Example: at stage level 40 and 2 kills a second, a chest takes 1,215 kills, one every 10.1 min.

The "seconds" are measured with the game's own estimate of your kill speed, not the clock on the wall, so real timings can drift. Offline progress gives no chests at all.

Stage-boss chests

Every stage boss (stages 1 to 9, whether you move on or repeat the stage) has a 50% chance to give one.
That roll only counts once 30 min worth of kills (at your current kill speed) have passed since your last stage-boss chest, so at most about one per 30 min of fighting.
The first stage boss of a new save always gives one.

Act-boss chests

Every act-boss win (stage 10 of an act) gives exactly one act-boss chest.
The fight costs one riftstone of that map, taken from the bag first, then the stash. A win spends it.
The fight will not start while your act-boss chests are at their cap ("open a red chest first"), and the riftstone is not spent. So act-boss chests are never lost.

Caps, queue and lost chests

Each tier has a cap on unopened chests, and all chests share a queue of 60. A common or stage-boss chest earned while its tier or the queue is full is lost. Codex runes raise the caps:

Chest	Base	Codex runes	Max
Common chest	6	Brown Coffer I, Brown Coffer II, Brown Coffer III, Brown Coffer IV, Brown Coffer V, Brown Coffer VI, Brown Coffer VII, Harvest, Cornucopia, Horn of Plenty	16
Stage-boss chest	4	Blue Coffer I, Blue Coffer II, Blue Coffer III, Blue Coffer IV	8
Act-boss chest	2	Red Coffer I, Red Coffer II	4

Harvest, Cornucopia and Horn of Plenty name no tier, so the game adds them to the common-chest cap.

Opening and auto-open

Chests are opened by hand, and a full bag blocks opening ("Bag full - make room to open this chest"). A Codex rune per tier unlocks an auto-open toggle that opens one chest of that tier on a timer; more runes shorten the timer:

Chest	Auto-open rune	Timer	Faster with	Fastest
Common chest	Rune of Vigil	15 min	10 runes, −30 s each	10 min
Stage-boss chest	Rune of the Keen Eye	1 h	6 runes, −5 min each	30 min
Act-boss chest	Rune of the Crimson Seal	1 min	5 runes, −10 s each	10 s

Rune of Gathering: the spacebar collects every chest. Rune of the Magnet: right-click collects every chest of one tier. Online, stage-boss and act-boss chests can arrive sealed, and open once the server sends their roll.

Not documented yet

Whether Codex and pet Luck count once for the party or once per hero. That changes real Luck totals.

Source: closed-beta game client 0.7.2. Data from the closed beta, so values may change at launch. Rates use the balance settings bundled with the client, which are much stingier than the code's fallbacks.