With weighted treasure randomizations (Tpro and Twildish), the contents of treasure chests and quest rewards are selected based on a weighted probability, which differs according to their location.

When assigning a random reward item based on a curve:

• The randomizer selects an item tier at random, based on the weighting.
• A random item is then selected from the options within that tier. (See item stats tables for item tier information.)

Twildish applies a transformation to the Tpro weights in order to boost item quality, as follows:

• new tier 1 weight = (old tier 1) * 7/8
• new tier 2 weight = (old tier 1) * 1/8 + (old tier 2) * 6/8
• new tier 3 weight = (old tier 2) * 2/8 + (old tier 3) * 5/8
• new tier 4 weight = (old tier 3) * 3/8 + (old tier 4) * 4/8
• new tier 5 weight = (old tier 4) * 4/8 + (old tier 5) * 3/8
• new tier 6 weight = (old tier 5) * 5/8 + (old tier 6) * 2/8
• new tier 7 weight = (old tier 6) * 6/8 + (old tier 7) * 1/8
• new tier 8 weight = (old tier 7) * 7/8 + (old tier 8)

The following are the approximate weights for Twildish, calculated based on the formulas above. The Tpro weights are available here.

Note that Tmaxtier:6 will prevent tier 7+ items from appearing in regular (non-MIAB) chests. If a chest would contain a tier 7+ item, instead its tier is randomly re-selected.

Each chest receives its item based on the area where the chest is found.

Monster-in-a-box rewards have their own distinct weightings:

Potential key item locations that do not award a key item (other than MIABs, which are described above) receive rewards based on the weighting below. (“Ungated” quests are quests that can be completed without access to any key items.)