What Pokémon Amethyst changes

Level caps

Chosen when a save starts and changeable from the second options page. With soft caps (the default) Pokémon level freely but stop obeying above the cap for your badge count. With hard caps, Pokémon gain 1 EXP once they reach the cap and Rare Candies will not push them past it; the Hard cap equals the next boss's ace and the Extra Hard cap sits two levels under it (except the last). The Hard column below is what the game uses on the Hard and Extra Hard difficulties, where bosses are a level or two higher.

Soft caps by badge count: 0 badges → 15, 1 badge → 25, 2 badges → 35, 3 badges → 45, 4 badges → 55, 5 badges → 65, 6 badges → 75, 7 badges → 85, 8 badges → 100.

The eight gyms

Kulure's gyms specialise in a battle mechanic rather than a type. Gyms three to five can be taken in any order, and Raine and Chance carry stronger teams if fought later.

HMs and badges

TMs are infinite. HMs work in the field without being taught, as long as you hold the badge, and can be forgotten at any time. Waterfall exists as TM98 but has no field use; Flash and Dive are not in the game.

Standard, Hard and Extra Hard

Standard: trainers' Pokémon are evolved when at or above their evolution level, IVs depend on trainer class (a Bug Catcher has few, the Champion has 31s), no EVs or natures, items are rare, and AI flags follow the class.

Hard: every boss's Pokémon holds an item (except the first rival fight), bosses get one extra Pokémon if they have room, each Pokémon is a level higher (aces sometimes two) and boss AI is smarter.

Extra Hard (v1.3): the Hard teams, plus every trainer's Pokémon has 31 IVs and 252 EVs in its two best stats.

The setting can be changed at any time from the second options page.

Gigantamax forms turned into Megas

Every official Mega is unchanged. The Pokémon that had a Gigantamax form in Sword and Shield instead get a new Mega Evolution designed by the creator, listed here with its type, ability and base stats. Their stones are sold by the Mega Stone Refiner on Route 11 once the Team Pluto event there is done; the first-partner ones use a -G suffix (Venusaurite-G and so on) because the official Mega is also in the game.

PokéChips

A second currency dropped after wild battles: 20% of the time, 45% with the PokéChip Charm, plus 15% if the battle was started with Sweet Scent or Honey. They pay for move tutors (5 or 10 chips a move), apricorn balls in Laplaz Town (2 chips, once a day), ball swapping in Bruccie Village and the PokéChip Crusher in Tsarvosa City, which turns chips into Max Revives (5), PP Max or Rare Candy (10), Bottle Caps or Ability Capsules (15), Ability Patches (25), Gold Bottle Caps (35) and a Master Ball (50).

Battle changes

Frostbite replaces freeze: 1/16 HP a turn and halved Special Attack, a special burn. Dark grass has a 50% chance of a wild double battle, and nothing can be caught until the other Pokémon faints.

Critical captures scale with how many species you have caught, from 0% below 30 species to 2% above 350 for a full-HP catch-rate-30 target in a Poké Ball; the Catch Charm from Heleo City doubles it.

Type icons appear before each turn, gym leaders and rivals get mugshots and mid-battle slide-ins, and Mega Evolution is unlocked after the Route 11 South Team Pluto event.

Swarms, roamers and trap Pokémon

One route a day has a swarm: a regional variant replaces a native species half the time, and the Swarm Swami in Heleo City says which. Catching the swarming Pokémon registers its Kulure equivalent as caught. Showing the Swami's assistant a swarm variant earns a Bottle Cap the first time, and a Gold Bottle Cap for the full set.

Galarian Articuno, Zapdos and Moltres roam the mainland from Lake Laplaz and Zeraora roams the island from Mimmett Jungle; a 25% chance of the fight on their route, and fainted roamers return after the next Hall of Fame visit.

Sandygast and Palossand pose as sandcastles, Foongus and Amoonguss as slightly small Poké Balls, and Stunfisk as tiny toothed ball icons.

What your starters change

Starters are shuffled across Generations 1 to 8 on every new save unless you lock a generation. The Grass starter's generation decides the free Daycare egg (Pichu, Togepi, Wynaut, Riolu, Larvesta, Happiny, Eevee or Toxel), the Fire starter's decides which trade is offered in Daimyn City, and the Water starter's decides which Eeveelution the rival ends up with (Vaporeon through Sylveon, in generation order).