The 3.2 boss randomization is a rework of the previous boss randomization feature. Where the legacy boss randomization only swapped single-target bosses with other single-target bosses and did the same for double-target bosses (leaving bosses with 3 or more targets as they were), the newer version does a much better job of mixing them up. Single- and double-target bosses can not only mingle with each other, but with few exceptions, bosses with 3 or more targets are now part of the shuffled pool as well.
The following bosses will never be shuffled from their space, even with Boss Randomization enabled (note the boss pool has grown!):
The following bosses are eligible to be shuffled when Boss Randomization is turned on. The “level” column denotes the power of the boss in its vanilla spot; this number is compared to the target boss spot's level when the boss is shuffled and power is scaled by comparing its original power to the target power.
| Level | Boss(es) |
|---|---|
| 1 | Yakra |
| 5 | Zombor |
| 8 | Heckran |
| 12 | Guardian & Bits Masa&Mune Retinite Yakra XIII |
| 14 | Atropos XR Flea Flea Plus Mother Brain Nizbel Slash Super Slash |
| 15 | Dragon Tank Golem Boss Mud Imp R-Series Rust Tyrano |
| 16 | Nizbel II |
| 18 | Golem Lavos Spawn Son of Sun |
| 20 | Giga Gaia Dalton Plus |
| 25 | Twin Boss (each) |
| 30 | North Cape Magus(?) Elder Spawn Giga Mutant Mega Mutant Terra Mutant |
In 3.2 Boss Randomization, the twin boss in the Ocean Palace is not treated as a separate “single” slot with two targets as it was before - it can now be a repeated “twin” of a boss that players have already seen in the seed. The major things to note are that having already seen a boss does not exclude it from appearing in the Ocean Palace and Dalton Plus is now eligible for the Twin Boss slot (previously he was banned from it for being too difficult - balance changes have also been made to accommodate this).
Boss Randomization is toggled on the main page of the web generator. The Boss Rando tab up above contains extra options for customization.
When Legacy Boss Placement is enabled, bosses will be shuffled according to 3.1.1 rules: only one-part bosses will be swapped with other one-part bosses, two-part bosses will likewise shuffled, and bosses with three or more parts like Retinite and Son of Sun will remain in their vanilla locations. See the legacy boss randomization page for a full list.
By default, boss randomization uses a formula to scale boss HP depending on the location where it's slotted. There is a spreadsheet of this info from the guides page.
However, enabling the Boss Spot HP option gives us a formula for Boss HP based on the space they appear (ie the back of the Cathedral or Heckran's Cave).
A full table of values is in the works.
Generally, boss spot HP is calculated by distributing the total HP value of that spot (for example, Heckran has 2100 HP so the Heckran Cave boss spot has 2100 HP) between the essential parts of a boss, ie the parts you must kill to win the fight (Guardian's bits or a Lavos Spawn's shell are not essential, but the bottom part of Mega or Giga Mutant is essential).
Nonessential parts will have their HP value assigned to them based on the original ratio of their HP to their main part's HP (Guardian's bits always have 25% of the max HP of the Guardian).
Some bosses use unique ratios to derive their HP from the spot they've been shuffled to: