The mechanics are pretty simple. If you open a chest, you'll get loot. There are 6 tiers of loot the game can pull from, which differs from dungeon to dungeon. When opening a chest, the game first chooses the tier of loot you'll get, then it rolls on the actual loot table there. The loot tables are detailed in their own sections later in the guide.

After the Hall of Trials, there's bad luck protection in place, allowing you to get higher tier loot more frequently. For each chest you open, the chances of getting higher tier loot increases, but this eventually caps after enough chests. Nothing can decrease the bad luck protection other than leaving a dungeon, where it resets back to the initial values. So the longer you stay in a dungeon, the more likely you'll get higher tier loot.

Trapped chests are generated beforehand when a floor is generated, so whether a chest is trapped or not is predetermined, namely so trap detection abilities like Charme's passive ability can function. Trapped chests have absolutely no effect on bad luck protection. There is no benefit to opening such a chest if you know it is trapped, so don't waste your time by doing so.

Hall of Trials:

• You will always get tier 1 loot.

Jade Way:

• Tier 1 loot is gained at a 100% rate until 3 chests are opened. Then the rate decreases by 2% per chest. This is capped at 80%, which is reached after opening 12 chests.
  
• Tier 2 loot is gained at a 0% rate until 3 chests are opened. Then the rate increases by 2% per chest. This is capped at 20%, which is reached after opening 13 chests.

The chest at the end of Jade Way is guaranteed to have a Very Odd Vase the first time you open it. On subsequent visits, it just acts like a normal chest.

Amber Garden:

• Tier 1 loot is gained at a 96% rate until 2 chests are opened. Then the rate decreases by 4% per chest.
  
  • After 4 total chests are opened, the rate decreases by 4.5% per chest.
    
  • After 6 total chests are opened, the rate decreases by 0.5% per chest. This is capped at 75%, which is reached after opening 13 chests.
• Tier 2 loot is gained at a 4% rate until 2 chests are opened. Then the rate increases by 4% per chest. This is capped at 20%, which is reached after opening 6 chests.
  
• Tier 3 loot is gained at a 0% rate until 4 chests are opened. Then the rate increases by 0.5% per chest. This is capped at 5%, which is reached after opening 14 chests.

The boxes that contain items in Tielle's boss fight count as chests and use the same rates and mechanics. Boxes that do not contain items do not increase the drop rate. Finding Tielle first does not count the unopened boxes in your favor.

Obsidian Tower:

• Tier 2 loot is gained at a 96% rate until 2 chests are opened. Then the rate decreases by 4% per chest.
  
  • After 4 total chests are opened, the rate decreases by 4.5% per chest.
    
  • After 6 total chests are opened, the rate decreases by 0.5% per chest. This is capped at 75%, which is reached after opening 13 chests.
• Tier 3 loot is gained at a 4% rate until 2 chests are opened. Then the rate increases by 4% per chest. This is capped at 20%, which is reached after opening 6 chests.
  
• Tier 4 loot is gained at a 0% rate until 4 chests are opened. Then the rate increases by 0.5% per chest. This is capped at 5%, which is reached after opening 14 chests.

Lapis Ruins:

• Tier 3 loot is gained at a 96% rate until 2 chests are opened. Then the rate decreases by 4% per chest.
  
  • After 4 total chests are opened, the rate decreases by 4.5% per chest.
    
  • After 6 total chests are opened, the rate decreases by 0.5% per chest. This is capped at 75%, which is reached after opening 13 chests.
• Tier 4 loot is gained at a 4% rate until 2 chests are opened. Then the rate increases by 4% per chest. This is capped at 20%, which is reached after opening 6 chests.
  
• Tier 5 loot is gained at a 0% rate until 4 chests are opened. Then the rate increases by 0.5% per chest. This is capped at 5%, which is reached after opening 14 chests.

Crystal Nightmare:

• Tier 4 loot is gained at a 96% rate until 2 chests are opened. Then the rate decreases by 4% per chest.
  
  • After 4 total chests are opened, the rate decreases by 4.5% per chest.
    
  • After 6 total chests are opened, the rate decreases by 0.5% per chest. This is capped at 75%, which is reached after opening 13 chests.
• Tier 5 loot is gained at a 4% rate until 2 chests are opened. Then the rate increases by 4% per chest. This is capped at 20%, which is reached after opening 6 chests.
  
• Tier 6 loot is gained at a 0% rate until 4 chests are opened. Then the rate increases by 0.5% per chest. This is capped at 5%, which is reached after opening 14 chests.

The boxes that contain items in Tielle's boss fight in the Crystal Nightmare count as chests, unfortunately they use the same drop rates and mechanics as Lapis Ruins and use the same rates and mechanics there. Boxes that do not contain items do not increase the drop rate. Finding Tielle first does not count the unopened boxes in your favor.

The chests on floors 30 and 60 have entirely different mechanics, which are detailed in their own section.

*Due mistakes in the RNG code, the Worn Sword is set to a 11/264 chance instead of the intended 10/264 chance, and the Pot Stand is set to a 3/264 chance instead of the intended 4/264 chance.

*Due mistakes in the RNG code, the Knight's Blade is set to a 5/208 chance instead of the intended 4/208 chance, and the Goldfish Bowl is set to a 1/208 chance instead of the intended 2/208 chance.

*Due mistakes in the RNG code, the Breaker Sword is set to a 5/181 chance instead of the intended 4/181 chance, and the Messy Scroll is set to a 2/181 chance instead of the intended 3/181 chance.

*Due mistakes in the RNG code, the Crystal Sword is set to a 5/352 chance instead of the intended 4/352 chance, and the Ferromin L is set to a 1/352 chance instead of the intended 2/352 chance.

*Due mistakes in the RNG code, the Crystal Sword is set to a 9/439 chance instead of the intended 8/439 chance, and the Omega Ferromin is set to a 1/439 chance instead of the intended 2/439 chance.

*Due mistakes in the RNG code, the Demonbane is set to a 9/448 chance instead of the intended 8/448 chance, and the Omega Ferromin is set to a 1/448 chance instead of the intended 2/448 chance.

When you get to the end of the Crystal Nightmare on floor 30, or the end of its boss rush on floor 60, you'll enter the room pictured above.

When completing the boss rush, you'll always enter the room in the pictured state, with 3 chests to open. However if you're exploring the dungeon portion, the state of this room will differ depending on which floor you started from. If you started from floor 21, only the middle chest will be present. If you started from floor 11, only the middle and right chests will be present. And if you started all the way from floor 1, all 3 chests will be present.

Each chest actually has a different reward pool, which will be detailed in the sections below.

This chest will only spawn if you started from floor 1. If you started from the boss rush, this chest will always spawn.

This one is simple. It's guaranteed to give you tier 6 loot.

This chest will only spawn if you started from floor 11 or floor 1. If you started from the boss rush, this chest will always spawn.

This chest rolls combines all 6 tiers of loot together into 1 giant loot table. Resulting in an X out of 1892 chance to get any piece of chest loot in the game.

Due mistakes in the RNG code, the Worn Sword is set to a 11/1892 chance instead of the intended 10/1892 chance, and the Omega Ferromin is set to a 3/1892 chance instead of the intended 4/1892 chance. The RNG bugs from the other tables do not apply here.

This chest always spawns no matter what. However, its behavior can differ depending on where you started the dungeon.

If you started from floor 21, you have 2 possible loot tables the game will choose from. The rare loot table, or every single possible chest loot (Same mechanics as the right chest), with both having an equal possibility of happening.

If you started from floor 1, 11, or the boss rush, there are 3 possible loot tables instead. The rare loot table, or every single possible chest loot (Same mechanics as the right chest), or the ultra rare loot table, all having an equal possibility of happening.

The rare loot table is as follows:

• Soul Cleaver
  
• Dragon Fang
  
• Megaflame Staff
  
• Wyvern Wing
  
• Cobra Spear
  
• Dragon Buster
  
• Fire-Dragon Claw
  
• Gravity Cannon
  
• Gothic Outfit
  
• Gentleman's Suit
  
• Moonlight Robe
  
• Valkyrie Plate
  
• Legendary Armor
  
• Fairy Misanga
  
• Legendary Shield
  
• Kitty Hood
  
• Legendary Helm
  
• Love Charm
  
• Spirit Magatama
  
• Imperial Cape
  
• Diana's Heart
  
• Trailblazers

There are 22 items, all with an equal chance of being chosen. Notably, this is the only way to get the Soul Cleaver, as it only shows up in this pool. For best results, you're better off doing floor 21 runs until you get this.

The ultra rare loot table is as follows:

• Legendary Sword
  
• Assassin Blade
  
• Heaven's Key
  
• Ancient Bow
  
• Vacula Spear
  
• Divine Finger
  
• Dark Master Claw
  
• Phalanx Cannon
  
• Phoenix Garb
  
• Eos Robe
  
• Mythic Beast Plate
  
• Stoneform Armor
  
• Trinary Armband
  
• Blue Line Shield
  
• Emperor's Crown
  
• Golden Helm
  
• Fruitdrop Amulet
  
• Fisherman Flag
  
• Dragon's Mane
  
• Iron Sandals
  
• Heavenly Heels

There are 21 items, all with an equal chance of being chosen. All the items from this pool are chosen from the rarest possible items from the tier 6 loot table. However, there are some notable omissions.

• Ishtoril: Can be obtained in earlier tier chests.
  
• Victory Charm: A 2 in 448 chance from the tier 6 drop table, with no other way to obtain. Good luck.
  
• Soul Ring: One of the rarest pieces of loot from tier 4, 5, and 6's drop tables. Since this is on multiple drop tables, you're more likely to come across this at least.
  
• Dragon Ornament: A 2 in 448 chance from the tier 6 drop table, with no other way to obtain. Good luck.
  
• Book of Adventure: A 2 in 448 chance from the tier 6 drop table, with no other way to obtain. Good luck.
  
• Omega Ferromin: Thanks to a bug in the RNG, this item is one of the hardest items to obtain from a chest, which makes this omission extremely unfortunate. Especially since you need at least 3 to be able to fuse every item. It does show up on the tier 5 drop table along with the tier 6 drop table, which is a small comfort.