Item Pools
The list of items randomly placed in a seed is known as the Item Pool. Generally speaking, items in the Item Pool are divided into two categories: Majors (Morph Ball, Gravity Suit, Energy Tanks, etc.) and Minors (Missiles, Super Missiles, and Power Bombs). Major Items in the Item Pool are affected by the Item Split, Map Layout, and the inclusion of Extra DASH Items.
Item Split
The Item Split determines the valid locations where major items can be placed. DASH currently offers three Item Split options: Major/Minor, Full, and Chozo.
Major/Minor
34 major item locationsMajor items can be placed at any of the vanilla major item locations. For balance, the Energy Tank location at HiJump Boots is considered a minor location, and the Right Side Super Missile location in Wrecked Ship is considered a major location.
Full
100 major item locationsAny location can hold a major item.
Chozo
25 major item locationsSufficient items to beat the game are placed at Chozo statues and boss reward locations. This includes each unique major item plus 3 energy tanks, 1 reserve tank, 2 missile packs, 2 super missile packs, and 1 power bomb pack. These items are considered major items by the randomizer.
Extra DASH Items
DASH introduces new major items which can optionally be included in the item pool. This includes Double Jump, Heat Shield, Pressure Valve, and Charge Upgrades for certain Beam Modes.
Building Item Pools
This is the process followed when building an item pool:
Add one of every vanilla item type to the item pool except for Charge Beam (all vanilla majors, 1 energy tank, 1 reserve tank, 1 missile, 1 super missile, 1 power bomb)
Either add Charge Beam to the item pool or the appropriate number of Charge Upgrades based on the Beam Mode
Add any extra DASH items to the pool (Double Jump, Heat Shield, or Pressure Valve)
Add energy tanks and reserve tanks based on the Item Split
Full - Item pool will contain a total of 14 energy tanks and 4 reserve tanks.
Major/Minor - With limited major locations, the number of energy and reserve tanks can vary. We want to place all 14 energy tanks so we initially reduce the number of reserve tanks down to a minimum of 2 if needed. Energy tanks are added to fill in the rest.
Chozo - 3 energy tanks and 1 reserve tank are added as major items. Additional tanks are added as minor items so that we end up with 14 total energy tanks and 4 total reserve tanks in the pool.
Add minor items to the item pool based on the selected ratio (3:2:1 or 2:1:1) until there are 100 items. Given a 3:2:1 ratio, every item added to the pool has a 3/6 chance of being a missile, 2/6 chance of being a super, and 1/6 chance of being a power bomb.