Surprise Bosses

Surprise bosses allows any boss to be at any location including duplicates. Defeating a boss opens access to the area in which it is placed (example: Kraid's etank will be accessible after defeating whatever boss is in Kraid's Lair). At least one boss will not be at its vanilla location.

Because Boss Surprise can introduce duplicates of bosses, it is possible that the number of item locations can change based on the number of Phantoons in the game. This is because Phantoon does not have an item location connected directly to the boss room. For example, having two Phantoons in a seed will result in 99 item locations instead of the vanilla 100 locations. With that in mind, the number of item locations are as follows:

0 Phantoons=101 item locations
1 Phantoon =100 item locations
2 Phantoons =99 item locations
3 Phantoons =98 item locations
4 Phantoons =97 item locations


When using the Full Item Split, the potential impact is reduced because only minor items are randomly added or removed as needed to account for the different number of item locations.


For Major / Minor Item Split, the item locations added/removed are major item locations. First it considers if extra DASH items (double jump, etc.) are included. If so, they can fill in an extra major item location in the 0 Phantoons case. Note that under normal circumstances, Reserve Tanks and Energy Tanks are dropped when extra DASH items are included, which can also play into the items in the major pool.

If there are no extra DASH items, here is the breakdown of how the major item pool changes based on the different number of Phantoons:

0 Phantoons101 locations1 Energy Tank added
1 Phantoon100 locationsNo Change
2 Phantoons 99 locations1 Reserve Tank removed
3 Phantoons98 locations2 Reserve Tanks removed
4 Phantoons 97 locations2 Reserve Tanks & 1 Energy Tank removed

NOTE: All items in the Major Item pool can be placed at any major item location, not just at boss locations. This means that when there are 0 Phantoons in a seed, the extra energy tank can appear at any major location, not just in the boss room locations.


For Chozo Item Split, the item locations are chozo item locations. There are normally 25 chozo item locations but that is also impacted by the number of Phantoons. Extra DASH items (Double Jump, etc.) are never placed at chozo item locations.

0 Phantoons26 locations1 Extra Chozo Energy Tank added (4 total)
1 Phantoon25 locationsNo Change
2 Phantoons 24 locationsChozo Reserve placed at non-chozo location
3 Phantoons23 locationsChozo Reserve and 1 Chozo Missile Pack placed at non-chozo locations
4 Phantoons 22 locationsChozo Reserve, 1 Chozo Missile Pack, and 1 Chozo Super Pack placed at non-chozo locations

NOTE: We recognize that removing the missile pack and super missile pack for the 3+ Phantoon cases technically makes it required to gather non-Chozo minor items to finish the game due to the need to break Mother Brain’s glass. We chose this over moving other “traditional” major items out of the Chozo Item pool. We are open to player feedback about potential changes to this choice in the future.