There are several randomization levels to customize the contents of the treasure chests throughout the world. (Note that “treasure chests” also refers to treasures in pots, bookshelves, etc.)

Note that all randomization levels treat monster-in-a-box (MIAB) chest differently from regular chests. Except where otherwise noted, the discussion below generally refers to regular chests.

Additionally, the chests containing the Rat Tail and Ribbons in vanilla FF4 are handled by the key item randomizer logic, and are not affected by the behaviors detailed here.

Under Tvanilla, chests contain the same items as they did in the Japanese version of FF4. MIAB chests deliver the same rewards as in the Japanese version of FF4 as well.

If Japanese-exclusive items are excluded from treasure chests (see below), chest contents match the US version of Final Fantasy IV instead.

Under Tshuffle, chests overall contain the same contents as in Tvanilla, but they are shuffled so they appear in different locations.

Regular chests are shuffled separately from MIAB chests. Regular chest contents from the overworld tend to remain in the overworld, and likewise for non-overworld chests. Specifically:

• Overworld chest contents are placed in pool 1, and underworld/moon chest contents are placed in pool 2.
• 50% of each pool is extracted and combined into pool 3.
• The pool 3 items are randomly redistributed back into pools 1 and 2, to restore them to their original sizes.
• Pool 1 treasures are randomly assigned to overworld chests, and pool 2 treasures are randomly assigned to underworld and moon chests.

MIAB chest rewards are shuffled into a single pool, along with the vanilla summon and moon rewards. Non-key-item rewards are taken from this pool, and the rest are distributed at random among the original locations, without regard to where they came from. See: Key Item Randomization

Tstandard, Tpro, Twild and Twildish select random contents to populate each chest, with varying distributions.

Tstandard and Twild are unweighted distributions. That is, the location of the chest does not affect the probability of its contents. Instead, the chest contents are chosen uniformly from the full list of items within the given tier restrictions.

• Under Tstandard, each chest contains a random item from tiers 1-5.
• Under Twild, each chest contains a random item from tiers 1-8.
• Under both, monster-in-a-box chests contain a random item from tiers 5-8.

Tpro and Twildish are weighted distributions; chests in different locations have different probabilities of containing strong vs. weak items. MIABs also have their own distributions. For full probability information, see Treasure probability curves.

Applying Tmaxtier: in conjunction with any of these settings will prevent items of higher tiers from appearing in regular chests. The relative weights for each remaining tier remain the same. Valid values are 3 through 7. (e.g., with Tmaxtier:4, no items of tier 5 or higher will appear in non-MIAB chests)

Similarly, Tmintier: will prevent items of lower tiers from appearing in regular chests. Valid values are 3 through 5.

Players seeking a challenge can use the Tempty flag to remove all treasures from regular chests. MIAB chests and non-KI rewards are treated the same as in Tpro.

For a similar, less extensive effect, the other randomization levels may be combined with a Tsparse: flag, which removes all but a specified percentage of regular chests.

To reduce busywork, chests rendered empty by Tempty or Tsparse begin the game already opened, so you can tell at a glance whether they need to be checked.

If other flags force items into treasure chests (for example, a Dark Matter Hunt), those choices are made after the randomization is applied, and overwrite the previous chest contents.

Setting Tno:j will exclude Japanese-version exclusive items from appearing in chests.

Normally, tier 1 items in chests are replaced with an equivalent amount of GP, to prevent cluttering up the inventory with weak items. Enable the Tjunk flag to keep tier 1 items as they are. Alternatively, applying Tmoney will swap the contents of ALL regular chests with equivalent GP. (The amount of GP is based on the item's sell price, which in turn is affected by flags that change item sale prices.)

MIAB chests are randomly relocated within their respective dungeons. For example, Eblan Castle contains three MIABs with the same fights as usual, just in different locations.

Note that for technical reasons, the MIAB chest in Upper Bab-il will always be positioned somewhere before the drop to the underworld.

Setting the -vanilla:miabs flag will force MIAB chests to remain in their original positions.